Journal Club CE Quiz 2017-1 PAGE

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Leadership Donors to The LSUHSC Foundation Department of Periodontics Fund may be granted credit for continuing education hours after completing a short online quiz at the end of each journal club session. All participants must complete the Evaluation and Opinion Questionnaire form provided at the bottom of each quiz.  CE certificates will be emailed usually within 2 weeks following quiz submission. CE Records will be maintained by the site administrator for a period of 5 years.  The CE opportunity is not open to the the dental community in general.  It is limited strictly to donors of The LSUHSC Foundation.

This continuing education opportunity is not affiliated with The Louisiana Academy of Continuing Education from LSU Health New Orleans Continuing Dental Education. Additional advanced education opportunities from them may be found at: https://www.lsucde.org

CONTINUING EDUCATION CREDIT
CE credit awarded for a participation in a course or activity may not apply toward license renewal in all states. It is the responsibility of each participant to verify the requirements of his or her state licensing board.

Questions

DesignedBy StevenJ. Spindler, DDS LLC

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Journal Club CE Quiz 2016-8

HOME 

Leadership Donors to The LSUHSC Foundation Department of Periodontics Fund may be granted credit for continuing education hours after completing a short online quiz at the end of each journal club session. All participants must complete the Evaluation and Opinion Questionnaire form provided at the bottom of each quiz.  CE certificates will be emailed usually within 2 weeks following quiz submission. CE Records will be maintained by the site administrator for a period of 5 years.  The CE opportunity is not open to the the dental community in general.  It is limited strictly to donors of The LSUHSC Foundation.

This continuing education opportunity is not affiliated with The Louisiana Academy of Continuing Education from LSU Health New Orleans Continuing Dental Education. Additional advanced education opportunities from them may be found at: https://www.lsucde.org

CONTINUING EDUCATION CREDIT
CE credit awarded for a participation in a course or activity may not apply toward license renewal in all states. It is the responsibility of each participant to verify the requirements of his or her state licensing board.

Questions

DesignedBy StevenJ. Spindler, DDS LLC

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Implants – Treatment Planning II

HOME Implant Home 

 Medical History: Effects of Age, Perio compromised patients

Age at Placement (growth);

  1. Oesterle LJ, Cronin RJ Jr. Adult growth, aging, and the single-tooth implant. Int J Oral Maxillofac Implants 2000;15(2):252-260.

  2. Cronin RJ Jr, Oesterle LJ. Implant use in growing patients. Treatment planning concerns. Dent Clin North Am 1998;42(1):1-34.

  3. Cronin RJ Jr, Oesterle LJ, Ranly DM. Mandibular implants and the growing patient. Int J Oral Maxillofac Implants 1994;9(1):55-62.

  4. Oesterle LJ, Cronin RJ Jr, Ranly DM. Maxillary implants and the growing patient. Int J Oral Maxillofac Implants 1993;8(4):377-387.

  5. Heij D eta al: Facial development, continuous tooth eruption and mesial drift as compromising factors for implant placement. Int J Ora Maxillofac Implants. 2006 Nov-Dec; 21(6)867-78

  6. Fudalej P., Kokich V., Leroux B: Determinig the cessation of vertical growth of the craniofacial structures to facilitate placement of single-tooth implants. Am J Orthod Dentofacial Orthop. 2007 Apr; 131 (4 Suppl):S59-67

  7. Heuberer S, Dvorak G, Mayer C, Watzek G, Zechner W. Dental implants are a viable alternative for compensating oligodontia in adolescents. Clin Oral Implants Res. 2014 Jan 3. doi: 10.1111/clr.12323. [Epub ahead of print]

Age at placement (outcome):

  1. Heij DG, Opdebeeck H, van Steenberghe D, Quirynen M. Age as compromising factor for implant insertion. Periodontol 2000 2003; 33:172-184.

  2. Meijer HJ, Batenburg RH, Raghoebar GM. Influence of patient age on the success rate of dental implants supporting an overdenture in an edentulous mandible: a 3-year prospective study. Int J Oral Maxillofac Implants. 2001 Jul-Aug;16(4):522-6.

  3. Moy PK, Medina D, Shetty V, Aghaloo TL. Dental implant failure rates and associated risk factors. Int J Oral Maxillofac Implants. 2005 Jul-Aug;20(4):569-77

  4. Schwartz-Arad D, Bichacho N. Effect of Age on Single Implant Submersion Rate in the Central Maxillary Incisor Region: A Long-Term Retrospective Study. Clin Implant Dent Relat Res. 2013 Aug 5. doi: 10.1111/cid.12131. [Epub ahead of print]

Periodontal disease

  1. Wennstrom, Lang. Treatment planning for Implant Therapy in the Periodontally Compromised Patient. (CH 22). Clinical Periodontology and Implant Dentistry, Lindhe, J.; Lang, K. 5th Edition, 2008, Blackwell Munksgaard (Volume 2).

  2. Karoussis IK, Kotsovilis S, Fourmousis I. A comprehensive and critical review of dental implant prognosis in periodontally compromised partially edentulous patients. Clin Oral Implants Res. 2007 Dec;18(6):669-79

  3. Karroussis, I et al: A comprehensive and critical review of dental implant prognosis in periodontally compromised partially edentulous patients. Clin Oral Impl. Res 18, 2007; 669-679

  4. Ong CT, Ivanovski S, et al. Systematic review of implant outcomes in treated periodontitis subjects. J Clin Periodontol. 2008 May;35(5):438-62.

  5. Mengel R, Flores-de-Jacoby L. Implants in patients treated for generalized aggressive and chronic periodontitis: a 3-year prospective longitudinal study. J Periodontol. 2005 Apr;76(4):534-43.

  6. Kim KK, Sung HM. Outcomes of dental implant treatment in patients with generalized aggressive periodontitis: a systematic review. J Adv Prosthodont. 2012 Nov;4(4):210-7.

  7. Roccuzzo M, Bonino L, Dalmasso P, Aglietta M. Long-term results of a three arms prospective cohort study on implants in periodontally compromised patients: 10-year data around sandblasted and acid-etched (SLA) surface. Clin Oral Implants Res. 2013 Jul 19. doi: 10.1111/clr.12227. [Epub ahead of print]


Topic:Skeletal growth and implant placement.

Authors: Oesterle LJ, Cronin RJ Jr.

Title:Adult growth, aging, and the single-tooth implant

Source: Int J Oral Maxillofac Implants 2000;15(2):252-260.

Type: Discussion

Rating: Good

PURPOSE: This paper addresses growth of the maxilla and the development of the maxillary dentition in the context of implant treatment

Maxillary Skeletal Growth

  • Anteroposterior Skeletal Changes. The midface grows generally in a downward and forward direction (arrow) relative to the anterior cranial base

Maxillary enlargement is variable between individuals and is particularly important to implant behavior. The jaw of patient V132 grew more downward than forward, while the jaw of patient V177 grew more forward than downward

  • Transverse Skeletal Changes.As transverse growth of the cranial base occurs, the midface expands in harmony, first at the sagittal sutures that run from the metopic suture of the frontal bone back to the foramen magnum, and later by drift remodeling after the sutures close.

Growth in width of the median suture accelerates at puberty and is the most significant factor in transverse growth of the maxilla.

The average increase in maxillary bone width varies from 5 to 8 mm from 4 years of age to adulthood. The increase in molar width was approximately 1 mm less than the maxillary increase

Transverse maxillary growth changes are not symmetric at the midpalatal suture. The increase in width at the posterior portion of the suture (6.7 mm) is three times the amount of increase at the anterior portion of the palate from 4 years of age to adulthood. This rotation results in the molars growing not only laterally, but also anteriorly, contributing to the decrease in arch length seen during development.

Vertical Skeletal Changes.Vertical growth of the maxilla occurs by sutural lowering (passive displacement) of the maxilla and apposition on the occlusal surfaces of the maxillary alveolus.

Mean growth changes from 4 years to adult:

O = amount of apposition at floor of the orbit.

Su = amount of sutural lowering of maxilla, which would carry an implant downward with the growth.

C = amount of apposition at the infrazygomatic crest, carrying the maxilla downward.

R = amount of resorptive lowering of the nasal floor.

A = the amount of appositional increase in the height of the alveolar process.

Vertical maxillary growth would dramatically affect an implant’s position. An implant placed in the growing maxilla at 4 years of age would behave like an ankylosed tooth. Increases in alveolar height by apposition and resorptive lowering of the nasal floor have the greatest effect on the implant. The osseointegrated implant would remain stationary in the alveolus, being buried by appositional bone growth on its occlusal surface and being exposed on its apical surface by resorptive lowering of the nasal cavity and sinuses. The closer to adulthood the implant is placed, the less the adverse effect.

Maxillary Dental Growth

  • Transverse Dental Changes: While dental width changes vary little with the primary dentition, a significant change in arch width occurs with eruption of the permanent teeth. In general, males have a greater increase in the molar areas than females.

Transverse dental changes. The arch width in the lateral incisor area increases 6 mm as the permanent incisors erupt, followed by a 1-mm decrease in width from 9 to 14 years of age but with little

change after 14 years of age, for a net increase of 5 mm

  • Anteroposterior Dental Changes.

A significant mesial shift of the teeth is seen relative to the body of the maxilla. Hence, while the maxillary dental arch increases in width, it also decreases anteroposteriorly in length and moves anteriorly as a unit.

Anteroposterior dental changes. Mesial repositioning of the maxillary dentition occurs during growth with 5 mm of change in the incisor area and nearly 4 mm in the permanent molar area reported in some studies. the molars moving mesially 5 mm and maxillary central incisors moving 2.5 mm. The decreased amount of incisor movement results in a “packing” of the incisors against the musculature with possible resultant crowding

  • Vertical Dental Changes.

Changes in the height of the palate partially reflect the increase in alveolar height. The results of studies are variable in their findings; however, in general there is an increase in palatal height as seen on dental casts

Much of the increase in total dental height increase is caused by the larger size of the permanent teeth as compared to the primary teeth. Most studies report an increase in posterior palatal height of from 4 to 6 mm, with more growth in males than in females. One study found an increase of only 2.5 mm in height

Maxillary Growth and the Osseointegrated Implant

  • As the maxilla moves downward and forward with growth, the alveolar process undergoes considerable remodeling and conformational changes.

  • An osseointegrated implant placed in the posterior alveolus of a young, growing maxilla may become significantly buried in bone, and its apical portion may become exposed as the nasal floor remodels occlusally.

  • Prostheses that cross the midpalatal suture and arc attached to implants may potentially restrict transverse growth.

  • Implants located on opposite sides of the midpalatal suture of a prepubertal child would be carried apart a significant distance by transverse growth.

Recommendations for the Placement of Implants in the Maxilla

  • Implants placed before the cessation of growth are unpredictable in their behavior

  • Rigid transpalatal prostheses in the prepubertal or early pubertal patient should be avoided to allow unrestricted transverse maxillary growth. Implants placed during the pubertal period have a greater likelihood of success, but still less than the postpubertal or postgrowth implant

  • The variation in growth from individual to individual in the amount and direction of change is great

  • Careful attention to maxillary growth and development will enable the dental implant team to provide the best possible care to the dentally disadvantaged young patient.

Topic:Age and implant placement

Authors: Cronin RJ Jr, Oesterle LJ

Title: Implant use in growing patients. Treatment planning concerns..

Source: Dent Clin North Am 1998;42(1):1-34.

Type: Discussion article:

Rating: Good

Keywords: age, growth, wrist

Discussion article:

  • Maxillary growth: the midface grows in a downward and forward direction relative to the anterior cranial face. Maxillary growth occurs as a result of both passive displacement and enlargement.

  • The average size of the dental arches is generally greater in males than in females. Female growth is nearly completed by age 15 and males growing is longer (age 17 to 19) and at a greater rate.

  • Tooth eruption and alveolar growth must be viewed as a negative factor in the placement of DI.

  • Implants in boys should be delayed longer than in adolescent girls.

  • The increase of alveolar height continue with eruption of the permanent incisors

  • The mandible grows downward and forward.

  • The mandible grows in length by growth at the condyle and ramus.

  • To accommodate posterior tooth eruption, the body of the mandible increases in length by resorption on the anterior aspect of the mandible and deposition on its posterior aspect.

  • As the mandible increases in length, it also increases in posterior width because of its V shape.

  • Girls generally erupt their teeth 2y earlier than boys.

  • Generally when the girls start menstruation, their growth is nearly complete. By age 15, most girls have nearly completed their growth, where areas many boys continue to grow into their early 20’s.

  • The longer growth period for males results in more prominent lower jaw and straighter profile seen in males.

  • There is no totally reliable indicator as to when growth has ceased. In fact long term studies indicate that growth never stops but continuous throughout life in the same direction as in adolescence but at a much reduce rate.

  • Long bone growth, particularly in the bones in the hand and wrist, is an indicator commonly used to male an educated guess of the status growth of the pt.

Topic: Mandibular growth and implants

Authors: Cronin RJ Jr, Oesterle LJ, Ranly DM.

Title: Mandibular implants and the growing patient.

Source: Int J Oral Maxillofac Implants 1994;9(1):55-62.

Type:Commentary

Rating: Good

Keywords: dental implants, growth and development, mandibular growth, osseointegration

Purpose:To discuss growth of the mandible and how this can affect implant placement in a growing patient.

Discussion:

Mandibular Growth Changes:

Anteroposterior growth:The mandible lengthens almost exclusively by posterosuperior growth of the condyle and posterior growth of the ramus. Ramus height is increasing 1-2 mm per year. Mandibular anterior width stabilizes relatively early and only increases slightly by appositional growth.

Rotational growth:The mandible exhibits a rotational pattern as it grows. The mandible “rolls” downward and forward. The center of rotation is situated near the incisal region. The goal is to upright the ramus, flatten the mandibular plane, and decrease the gonial angle. Patients can also have little rotational component. Children with a strong rotational pattern, implants would be carried inferior with the rolling pattern of the mandible and buried within the alveolar process. Implants could also be deficient in height and/or positioned at nonesthetic and nonfunctional inclinations.

Transverse changes:Changes in arch width vary greatly from individual to individual. It is impossible to predict intercanine width at age 15 based on intercanine mesaurements taken at 4-5 years old.

Dental height changes:From years 9—15 there is a steady increase in height of both incisors and molars. Measurements from the mandibular plane to the menton increases 12 mm in males and almost 7 mm in females between he ages of 6 and 16.

Arch length changes:Arch length changes occur as the mandible grows, the amount of cange varies with the direction of growth.

Mandibular changes and the Osseointegrated implant: Mandibular midline implants have a better prognosis in a young patient than those placed in other areas of the mandible. Prosthesis design must allow for the average increase in dental height of 5-6 mm and for the anteroposterior variation caused by different directions of growth. The burying of an implant because of occlusal alveolar bone apposition is possible in both the posterior and anterior segments. This can be exacerbated by an unfavorable rotational growth pattern. Girls grow actively until 14-15 years of age while boys grow longer and more abundantly until 17-18 years old.

Recommendations:

Whenever possible implant placement should be delayed until after age 15 for girls and age 18 for boys. The parents and patient should have informed consent that implants placed at an early age may not be “permanent” and may have to be reimplanted. If an implant is adversely affected by growth or causing adverse growth, it should be removed while the surgery is still uncomplicated.

Conclusion:When placed in the growing patient, dental implants should be closely monitored and carefully restored with implant prosthesis designed to accommodate growth and development. Implants placed after age 15 in girls and 18 in boys have the most predictable prognosis.

Topic:Age of Placement

Authors: Oesterle LJ, Cronin RJ Jr, Ranly DM

Title:Maxillary implants and the growing patient.

Source:Int J Oral Maxillofac Implants 1993;8(4):377-387.

Type:Review

Rating: Good

Keywords:dental implants, maxillary growth, osseointegration

Purpose: To addresses growth of the maxilla and the development of the maxillary dentition in the context of implant treatment.

Discussion:Maxillary skeletal and dental growth results in dramatic changes in all three dimensions during active growth. Experimental evidence and the behavior of ankylosed teeth suggest that an osseointegrated object remains stationary in the bone surrounding it and does not move or adapt to bone remodeling. Growth changes may result in the burying or loss of implants depending on the placement site. Hence, implants placed in the early mixed dentition have a poor prognosis of continued usefulness through puberty. When placed early, implants may disturb growth or have to be replaced. Implants placed during late puberty or early adulthood have the best change for long-term usefulness.

Conclusion: Osseointegrated implants in the maxilla of growing patients must be undertaken with a great deal of caution. Implants placed before the cessation of growth are unpredictable in their behavior.

Topic:Implants in younger individuals/children

Author:Heij D eta al

Title:Facial development, continuous tooth eruption and mesial drift as compromisisng factors for implant placement.

Source:Int J Ora Maxillofac Implants. 2006 Nov-Dec; 21(6)867-

Type:Discussion article

Rating:Good

Keywords:Implants, growing skeleton, implants in children

Discussion:

The replacement of teeth lost by children can be an important indication for early implant therapy. Osseointegrated dental implants, like ankylosed teeth, alter position as growth-related changes occur within the jawbones (displacement, remodeling, mesial drift). It has been shown that implants do not follow the growth/change of the alveolar process such as natural teeth. Skeletal growth in the close vicinity around implants are slowed, whereas they continue as normal pace elsewhere. Thus bony defects, occlusal scheme dysfunctions and adjacent tooth complications are seen. 

Facial growth of the child and even of the adolescent, as well as the continuous eruption of the adjacent anterior teeth, create significant risk of a less favorable esthetic and/or functional outcome. Jaw bone growth: Both the mandible and the axilla follow a distinct chronology: growth is first completed in the transversal plane, then in the sagittal plane, and finally, only at a later stage, in the coronal plane. The growth of the mandible is closely associated with growth in stature, whereas growth for the maxilla is more associated with growth of the cranial structures. Maxilla: intercanine arch width increases minimally after 10 years (0.9mm average), sagittal growth of maxilla typically is resorptive therefore implants placed in the anterior maxilla can come across the complication of buccal plate resorption and implant dehiscence, vertical growth of maxilla persists to 17-18 years of age in females, perhaps longer for males therefore until the age of 18 (approx.) there may be vertical plane issues. Mandible: transverse growth completes early in anterior region whereas continue substantially in premolar and molar region, therefore if implants are placed in that region before growth cease implants could result lingually, vertical growth is substantial for mandible and is therefore can be affected by presence of dental implants. For patients with a normal facial profile, the placement of an implant should be postponed until skeletal growth is complete. For patients with a short or long face type, further growth, especially the continuous eruption of adjacent teeth, creates a serious risk even after the age of 25 years. 

In order to determine proper timing for implant placement in adolescents/young adults it was suggested to examine:

Topic:  Treatment planning- Skeletal growth

Authors:Fudalej P., Kokich V., Leroux B:

Title: Determining the cessation of vertical growth of the craniofacial structures to facilitate placement of single-tooth implants.

Source: Am J Orthod Dentofacial Orthop. 2007 Apr; 131 (4 Suppl):S59-67

Type: Retrospective study

Rating: Good

Keywords: dental implant, cephalograms, puberty, facial skeleton growth

Background: Single-tooth implants are commonly used to replace congenitally missing teeth in adolescent orthodontic patients. However, if implants are placed before cessation of facial growth, they will submerge relative to the adjacent erupting teeth. Therefore, it is important to know when facial growth is complete in postpubertal orthodontic patients.

Purpose: To determine and quantify the amount of vertical growth of the facial skeleton and the amount of eruption of the central incisors and the maxillary first molars after puberty.

Methods:

Two or 3 lateral cephalograms taken at pretreatment, posttreatment, and 10 years post retention of 142 males and 159 females were evaluated. Linear regression models were used to determine changes in the parameters with increasing age.

Results:

The findings indicate that

(1) the growth of the facial skeleton continues after puberty

(2) there is a difference in the amount of growth between the sexes during the second decade of life, and after age 20 the intergender difference is substantially diminished

(3) the rate of eruption of the maxillary central incisors in females seems to be greater than in males.

Conclusion:

The growth of the facial skeleton continues after puberty, but the amount of growth decreases steadily and after the second decade of life seems to be clinically insignificant.

Topic:implants in young pts

Authors:HeubererS, Dvorak G, Mayer C, Watzek G, Zechner W

Title:Dental implants are a viable alternative for compensating oligodontia in adolescents.

Source: Clin Oral Implants Res. Jan 3. doi: 10.1111/clr.12323.

Type:clinical

Rating: good

Keywords:children, growth, young dentition

Purpose: To clinically and radiographically evaluate dental implant treatment in adolescents

with extensive oligodontia.

Methods: Patients with more than nine permanent teeth congenitally missing and implant

treatment before the age of 16 years were included. Clinical follow-ups involved bleeding on

probing, plaque index and peri-implant probing value. The peri-implant bone level was analyzed on panoramic radiographs at time of implant treatment and at follow-up. Characteristics of the dental implants and patients (gender, smoking status, position of the missing teeth and age at the time of implant placement) were gathered. The implant positions during maturation was evaluated measuring the center of the implant-abutment interface to a reference line.

Results: This study involved 18 patients (9 m/9 f) having 71 dental implants. 3 were smokers. Youngest patient was 6 yrs old. Number of missing teeth ranged from 10-26. 4 pts received overdentures and the rest, crowns. The tooth predominantly missing was lower left second premolar. Implants used were Nobel Biocare and Dentsply Friadent.

  • Mean age at the time of dental implant treatment was 12.5 years.

  • BOP was negative on 44% of the implants and positive in 32%. Mean PD was 3.6 mm.

  • The peri-implant bone level correlated significantly negative with the age at time of implant placement.

  • There were no SSD between bone loss and implant diameter, surface, length, PI, the region, and smoking habits.

  • Dental implant treatment in adolescents resulted in a survival rate of 89% (63/71) with a mean loading time of 11 years.

  • Thesuccess rate of the dental implants (criteria: peri-implant probing value ≤5 mm, bleeding on probing (BoP) negative, bone loss <0.2 mm) was evaluated on 54 dental implants and calculated as 17% (9/54, 5 patients).

  • 54% of the implant crowns (nine of 18 patients, 38 of 71 crowns) had to be renewed after a period of 7.8 years

Conclusion: The results demonstrate long-term survival of DIs in adolescents. However, more long-term studies are needed to further enhance dental implant treatment in maturing individuals with extensive oligodontia.

Topic:Age

Author:Heij DG, Opdebeeck H, van Steenberghe D, Quirynen M.

Title: Age as compromising factor for implant insertion.

Source:Periodontol 2000 2003; 33:172-184

Type: Review

Rating: Good

Keywords:Dental implants; age; maxilla growth/development; mandible growth/development

Purpose:The purpose of this review was to present the age considerations that need to be taken into account during the planning of dental implants.

Discussion:

  • Because of osseointegration, which resembles ankylosis, implants do not follow the spontaneous and continuous eruption of the natural dentition. Such implants may even disturb a normal development of the jawbones.

  • Installation of an implant should generally be postponed on average until after puberty or after the so-called growth spurt of the child.

  • Implants do not follow the formation and development of the alveolar process. At some distance from the implants, the tissues developed normally, but in the immediate vicinity of the implants, further development was slowed down. This can lead to unesthetic and non-functional situations (loss of occlusal contact) together with periodontal complications.

Recommendations by Area

  • Anterior Maxilla

    • Most risky site for early implant placement due to the amount, the direction, and the unpredictability of growth in this area

    • Premature implant placement can necessitate a repeated lengthening of the transgingival or transmucosal part of the implants

    • On a long-term basis, early placement can even adversely affect adjacent natural teeth.

    • Best strategy is to delay implant insertion until after skeletal growth has completed.

  • Posterior Maxilla

    • Large variations exist in the amount and direction of both sagittal and vertical growth, and the unpredictability of the growth pattern.

    • Since the vertical growth occurs by apposition on the alveolar aspect and resorption on the nasal or maxillary sinus area, an early inserted implant can become submerged occlusally and exposed apically.

    • Recommend delaying an implant placement until after cessation of growth.

  • Anterior Mandible

    • Transverse and sagittal growth are completed relatively early in this area.

    • Area seems to hold the greatest potential for early use of an implant supported prosthesis

    • Should avoid use of early implants in combination with natural teeth in that area.

  • Posterior Mandible

    • As the mandible undergoes rotational growth, significant changes occur in both the alveolus and the mandibular border, largely influence by the facial growth type.

    • Progressive Infraocclusion of the implant and harm to adjacent teeth preclude the early placement of dental implants in this area.

Topic:Implant patient age

Authors: Meijer HJ, Batenburg RH, Raghoebar GM

Title:Influence of patient age on the success rate of dental implants supporting an overdenture in an edentulous mandible: a 3-year prospective study

Source:Int J Oral Maxillofac Implants. 2001 Jul-Aug;16(4):522-6.

Type:Prospective study

Rating: Good

Keywords: Aging, dental implants, geriatric dentistry

Purpose: To compare selected clinical parameters in older and younger edentulous patients with an implant supported mandibular overdenture during a 3-year evaluation period.

Methods:Inclusion criteria included an edentulous period of at least 2 years and severe resorption of the mandibular ridge. All patients were treated with implants in the right and left canine region of the lower mandible. Implants were restored after 3 months with an overdenture supported by a round bar and clip attachment. The patients were divided into 2 groups based on age: the “younger” patient group (50 and below and the “older” age group (60 and above). Bone height and quality was measured at baseline when denture was placed, at 12 months after placement, and 36 months after placement with standardized intraoral radiographs and lateral cephalometric radiographs. Implant loss, plaque/calculus, inflammation, PD, and BOP were recorded.

Results: One implant was lost in the patient of the older group. The implant appeared to be mobile 3 months after placement. Another implant was successfully placed after 6 months. The only significant difference in clinical parameters noted in between groups was seen in plaque levels, with higher plaque levels observed in the older group.

Discussion: Clinical performance of implant-supported overdentures in the mandible was equally successful in younger and older patients. Increased plaque levels in older patients could be due to increased difficulty in manipulation of devices required to clean I-bars and abutments, however age should not be used as a reason to exclude patients from implant treatment.

Topic:Implant VI – Treatment Planning           implant failure rates and associated risk factors
Authors: Moy PK et al
Title: Dental implant failure rates and associated risk factors.

Source: Int J Oral Maxillofac Implants. 2005 Jul-Aug;20(4):569-77

Type:Retrospective Cohort

Rating: Very Good

Keywords: dental implants, implant failure, medical risk factors, osseointegration

Purpose: To test the hypothesis that coexisting conditions (such as smoking, diabetes, and radiation therapy) lead to increased rates of implant failure, a retrospective analysis of dental implants placed in a consistent manner by a single surgeon was carried out.

Method: a cohort study of consecutive series of patients who received dental implants by the same surgeon over a 21-year period. Medical history and risk factors including, age, gender, location of implant, smoking history and coexisting medical conditions such as diabetes, HP, coronary artery disease, asthma, steroids, chemotherapy and radiation and post-menopausal hormone replacement therapy were extracted from the records.

All implants were placed in a consistent protocol by the same surgeon. Follow up was up to 20 years by the surgeon or a hygienist, most implants were machined type, and failure was recorded when an implant was removed due to mobility, pain, infection, paresthesia or anesthesia and radiographic bone loss greater than 50%

Results:A total of 4,680 implants were placed in 1,140 patients between 1982 and 2003. Patients’ age ranged from 12 to 94 years and females were 59.4% of the study sample. 68% of patients had 1 or more coexisting condition and 6% had 3 or more conditions. 74% of patients had 1 to 5 implants, 26% had 6 or more implants and 1 patient had 24 implants. 85.1% of patients had successful implants; however, 14.9% experienced at least 1 implant failure.

Implants in the maxilla had twice the failure rate of those placed in the mandible. Failure rate in the maxilla is 8.16%, and failure rate in the mandible was 4.93%.

Diabetes, smoking, and head and neck radiation were significant predictors of implant failures. More implants failed in diabetics and those with previous head and neck radiation than in smokers. In smokers, most failures ocured within the first year. Diabetics had failures that continued over the following 10 years and radiation patients experienced most failures within the first 2 years but had fewer failures after 5 or 10 years.

Conclusion:some medical risk factors such as asthma, hypertension and chronic steroid therapy are not correlated with significant increase of dental implant failure. Only smoking, diabetes, head and neck radiation and postmenopausal hormone replacement therapy were associated with significant increase in implant failure. The study did not report any contraindications.

Topic: Biological Principles                   patient age on single implant submersion

Authors:Scwartz-Arad D, Bichacho N

Title:Effect of age on single implant submersion rate in the central maxillary incisor region: A long-term retrospective study.

Source:Clinical Implant Dentistry 2013; 1-6.

Type:Retrospective Study

Rating:Good

Keywords:age, dental implants, long term, and submersion rate

Background:It is contraindicated to place dental implants before growth and development are completed as they are at a risk of submersion due to growth arrest, creating a potential aesthetic problem.

Purpose:The present study evaluated the effect of age on mean submersion rate of single dental implant in the central maxillary incisor area placed after growth has ceased, as compared with the adjacent incisor natural tooth.

Materials and methods A retrospective study was conducted on 35 patients (mean age 29.3±9.9 years, 21 females) who received a single dental implant replacing a missing maxillary central incisor from 1992 to 2008 with a follow-up of at least 3 years. Clinical photos from last follow-up were digitally analyzed to measure the vertical change between the incisal edge of the implant supported crown and the adjacent natural central incisor.

Results:In the younger age group (30 years), the submersion rate was more than three times higher than in the older age group (>30 years), yielding submersion rates of 1.02 and 0.27% per year, respectively. Accordingly, significantly higher proportion of soft tissue complications was also observed in the younger age group as compared with the older one.

Conclusion:

Whereas implant submersion continues throughout adult life, its rate varies with age. It is evident that this phenomenon is much more conspicuous during the second and third decades of life as compared with the fourth and fifth.

Discussion:

If implants are placed before cessation of facial growth, they will submerge relative to the adjacent erupting teeth. Facial growth of the child or adolescent, as well as the continuous eruption of the adjacent anterior teeth, creates significant risk of a less favorable esthetic and/or functional outcome.

Topic: Treatment planning       Implants in periodontally compromised patients

Authors:Wennstrom & Lang

Title:Treatment planning for Implant Therapy in Periodontally Compromised Patient

Source:

Type:

Rating:Good

Keywords:treatment planning, prognosis, compromised patient

Developments in implant treatment options influence our decisions regarding the preservation of teeth with varying degrees of periodontal destruction

PROGNOSIS OF IMPLANT THERAPY IN PERIO COMPROMISED PATIENTS

Global data on implant survival indicate low incidence of implant loss

Question remains: do implants have better long-term prognosis than teeth?

Data from 5 & 10 year studies on perio patients with regular supportive care that incidence of tooth loss =2-5%; implants NOT BETTER THAN TEETH LONG-TERM in these studies.

Perio patients may have increased susceptibility to bone loss around implants.

STRATEGIES IN TREATMENT PLANNING

Comprehensive clinical and Radiographic exams are the basis for planning

Elimination of periodontal lesions prior to implant placement and establishment of high standard of infection control are decisive factors for successful implant therapy; if this is coupled with regular recall – the long term should be same as for patients without prior periodontal disease

POSTERIOR SEGMENTS-

Usually the most severely affected by PD and tooth loss

Tooth Vs. Implant

Is the tooth a critical tooth, or supporting C&B work (ie what is the functional value of the tooth?)

Could the tooth be saved via Sx or nonsurgical means? GTR?

What are the patient’s esthetic and functional demands?

If the tooth is extracted will sufficient bone exist to install an implant? Will sinus or more extensive grafting procedures be necessary to provide sufficient bone?

AGGRESSIVE PERIODONTITIS

Patients often respond to regenerative therapy. Wide, angular Defects are often present on teeth adjacent ones lost early and can often be saved with such regenerative techniques.

instead of dooming these teeth and initiating more complex implant supported restorations, GTR can often be done then limiting the number and complexity of implants otherwise required.

Success is ultimately attributable to high-quality infection control

FURCATION PROBLEMS

If root section is performed, do the future roots have enough interradicular periodontal support after endodontics to support a restoration?

Single-tooth in Esthetic Zone

Can the tooth be saved? Will inevitable consequences of therapy required to save tooth be acceptable (recession, black triangles)?

Topic:Periodontitis vs implant survival

AuthorsKaroussis IK, Kotsovilis S, Fourmousis I

Title: A comprehensive and critical review of dental implant prognosis in periodontally compromised partially edentulous patients.

Source: Clin Oral Implants Res. 2007 Dec;18(6):669-79

Type: Clinical study

Rating: Poor

Objectives: To examine the short-term (<5 years) and long-term ( >5 years) prognosis of osseointegrated implants placed in periodontally compromised partially edentulous patients.


Material and methods: Using the National Library Of Medicine and Cochrane Oral Health Group databases, a literature search for articles published up to and including August 2006 was performed. Out of 2987 potentially abstracts/ 15 prospective studies were selected, including 7 short-term and 8 long-term studies. Because of considerable discrepancies among these studies, meta-analysis was not performed.

Results:

  • Short-term survival rates in pt with history of chronic periodontitis: 90-100%

  • Long-term survival rate in pts with history of chronic periodontitis up to 97.32%

  • Two long term studies reported survival rates <90%, both of them included hollow implants many of which had a short length

  • 95% short-term and 88.8% 5-year survival rates in patients treated for aggressive periodontitis

  • In conclusion, the long-term survival rates of implants placed in partially edentulous patients with a history of chronic periodontitis are comparable to the mean implant survival rates reported for the general population

Conclusion:

    • Short-term survival rates comparable to periodontally healthy individuals, stability of PPD, CAL and peri-implant marginal bone loss

    • Long-term survival rates may exceed 90%

    • PDs and the proportion of deep pockets tend to increase throughout a long-term period

    • Effect on long-term marginal bone loss around implants is not yet clarified

    • Although surviving, implants in patients with history of periodontitis may demonstrate higher incidence of peri-implantitis

    • Insufficient data for patients with aggressive periodontitis at that time

Critics: Absence of universally accepted definition for “periodontally compromised” patients and criteria for implant success. According to these studies, the ‘periodontally compromised’ patients have a history of periodontitis (chronic or aggressive), but no active disease at the time of implant placement. Certain studies included a relatively limited number of patients. Several studies included smokers. Implant ‘success’ was defined in some cases only. In certain cases, sinus membrane elevation.

Topic: Periodontitis history

Authors:Karroussis, I

Title: A comprehensive and critical review of dental implant prognosis in peridontally compromised partially edentulous patients.

Source: Clin Oral Impl. Res 18, 2007; 669-679

Type: Systematic review

Rating: Good

Keywords: prognosis, periodontally compro

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Implant 5 – Treatment Planning I

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Medical History: medical conditions + drugs that may affect implant and surgical outcome; Risk factors

  1. Misch and Resnik. Medical Evaluation of the Dental Implant Patient (CH 20). pp 406-420. Contemporary Implant Dentistry, Misch, C.E., 3rd Edition, 2008, Mosby Year Book.

  2. Rose L and Mealey B. Implant complications associated with systemic disorders and medications. (CH 2) pp 9-45.

  3. Sugerman, P., Barber, M.: Patient selection for endossous dental implants; Oral and systemic considerations. Int J Oral Maxillofac Implants. 2002 Mar-Apr; 17(2):191-201

  4. Ong, C et al: Systematic Review of Implant Outcomes in Treated Periodontitis Subjects. J Clin Periodontol 2008; 35:438

  5. RasperiniG, Siciliano VI, et al. Crestal bone changes at teeth and implants in periodontally healthy and periodontally compromised patients. A 10-year comparative case-series study. J Periodontol. 2013 Nov 11. [Epub ahead of print]

  6. KlokkevoldP, Han T: How do smoking, diabetes and periodontits affect outcomes of implant treatment? Int J Oral Maxillofac Implants. 2007; 22 (suppl)173-202

  7. Dowel, S et al: Implant success in people with type 2 diabetes mellitus with varying glycemic control. A pilot study. JADA: 138:2007:355-361

  8. StrietzelFP, Reichart PA, et al. Smoking interferes with the prognosis of dental implant treatment: a systematic review and meta-analysis. J Clin Periodontol. 2007 Jun;34(6):523-44. Review.

  9. BainCA Implant installation in the smoking patient. Periodontol 2000. 2003;33:185-93. Review.

  10. Fugazzotto, P et al: Implant Placement with or without Simultaneous Tooth Extraction in Patients Taking Oral Bisphosphonates: Postoperative Healing, Early Follow up and Incidence of Complications in Two Private Practices. J Periodontol 2007; 78:1664-1669

  11. Colella, Cannavale, Pentenero, Gandolfo: Oral implants in radiated patients: A systematic review. Int J Orla Maxillofac Implants 2007; 22(4):616-623

  12. Holahan, C et al: Effect of osteoporotic status on the survival of titanium dental implants. Int J Oral Maxillofac Implants. 2008:Sep-Oct; 23(5)905-10

  13. ClaudyMP, Miguens SA Jr, et al Time Interval after Radiotherapy and Dental Implant Failure: Systematic Review of Observational Studies and Meta-Analysis. Clin Implant Dent Relat Res. 2013 Jun 7. [Epub ahead of print]

  14. SharafB, Dodson TB. Does the use of prophylactic antibiotics decrease implant failure? Oral Maxillofac Surg Clin North Am. 2011 Nov;23(4):547-50

  15. AhmadN, Saad N. Effects of antibiotics on dental implants: a review. J Clin Med Res. 2012 Feb;4(1):1-6.

  16. EspositoM, Grusovin MG, Worthington HV. Interventions for replacing missing teeth: antibiotics at dental implant placement to prevent complications. Cochrane Database Syst Rev. 2013 Jul 31;7:CD004152.

  17. Ata-AliJ, Ata-Ali F, Ata-Ali F. Do antibiotics decrease implant failure and postoperative infections? A systematic review and meta-analysis. Int J Oral Maxillofac Surg. 2013 Jun 25. pii: S0901-5027(13)00258-0. doi: 10.1016/j.ijom.2013.05.019. [Epub ahead of print]

  18. Alissa R, Sakka S, Oliver R, et al. Influence of ibuprofen on bone healing around dental implants: a randomised double-blind placebo-controlled clinical study. Eur J Oral Implantol. 2009 Autumn;2(3):185-99.


Topic:Patient selection

Author:Sugerman, P., Barber, M

Title:Patient selection for endossous dental implants; Oral and systemic considerations.

Source:J Oral Maxillofac Implants. 2002 Mar-Apr; 17(2):191-201

Type:Discussion

Rating: Good

Keywords:patient selection, endossous dental implant, oral, systemic consideration

Purpose:The aims of this article were to define “reasonable health” for dental implant treatment and to provide a systematic approach to the selection of dental implant patients.

Discussion:

TITANIUM TOXICOLOGY The survival or success of endosseous dental implants may be influenced by a number of local and systemic conditions. Some of these conditions affect the process of osseointegration directly. The following are noted in particular.

  • PHYSICAL STATUS

    • The American Society for Anesthesiology (ASA) has defined a 6-point scale of physical status

  • AGE

    • Younger patients may show greater crestal bone resorption around dental implants.It is therefore recommended that implant placement be delayed until growth and development have ceased or are minimal

    • However, implant failure does not correlate with age or sex. Increasing age has no effect on osseointegration or the rate of crestal bone resorption around dental implants.

  • PATIENT EXPECTATION

    • Although dental implants can enhance esthetics, phonetics, and bite force, it is important to identify unrealistic expectationsthat patients may have about implants and implant- retained prostheses.

  • HYPOHIDROTIC ECTODERMAL DYSPLASIA is characterized by hypodontia, hypotrichosis, and hypohidrosis. Dental implants have been used successfully in patients with severe hypodontia associated with ectodermal dysplasia.In a recent prospective study, implant placement and prosthetic rehabilitation in young children with ectodermal dysplasia did not restrict transverse or sagittal growth. However, vertical alveolar growth resulted in the occasional submergence of endosseous implants, necessitating revision and the placement of longer abutments.

  • SMOKING:Many studies have shown that smoking interferes with osseointegrationand accelerates bone resorption around dental implants

  • OSTEOPOROSIS:osteoporosis appears not to influence implant survival.Moreover,endosseous dental implants may actually stimulate mandibular bone formation in a load-dependent manner.

  • DIABETES MELLITUS: endosseous dental implants are usually successful in patients with diabetes, although uncontrolled diabetes contraindicates dental implant placement. Consideration should be given to antibiotic prophylaxis for surgical procedures in diabetic patients.

  • SCLERODERMA:little is known about dental implants in patients with scleroderma.Endosseous dental implants may improve prosthesis function and comfort in scleroderma patients, although access for implant surgery and for oral hygiene may be compromised.

  • SJÖGREN SYNDROME: Implant-supported prostheses were shown to considerably increase prosthetic comfort and function in patients with Sjögren syndrome,preferable to soft tissue-supported prostheses.

  • MULTIPLE MYELOMA: Implant success has been reported in a patient with multiple myeloma.Unmanaged malignant disease in general must be considered a contraindication for the placement of endosseous dental implants.

  • PARKINSON’S DISEASE: Implant- supported prostheses should be considered in patients with Parkinson’s diseaseand other diseases affecting orofacial motor function.

  • BONE MARROW TRANSPLANTATION: Implant placement should be delayeduntil cytotoxic chemotherapy has ended and the mar- row graft has taken. Bone marrow transplant patients may develop oral graft-versus-host disease that is clinically similar to oral lichen planus

  • HIV: endosseous dental implants have been placed successfully in HIV-positive patients

  • SYSTEMIC DRUGS: Consultation with the patient’s physicianprior to dental implant placement is desirable for patients on anticoagulants or long-term systemic corticosteroids.

  • CHRONICALLY INFECTED IMPLANT SITES: Periodontitis and periapical lesions should be diagnosed and treated prior to dental implant placement.

  • ORAL LICHEN PLANUS Endosseous dental implants may be used in patients with nonerosive forms of OLP, although patients should be warned of possible lesion exacerbation related to surgery and possible implant failure if gingival lesions become erosive

  • HEAD AND NECK RADIOTHERAPY: Implant placement following head and neck radiotherapy is associated with a significant risk of osteoradionecrosis, especially with irradiation above 50 Gy. Recommended a 6- to 12-month recovery period after irradiation prior to dental implant placement

Presurgical hyperbaric oxygen may reduce the dental implant failure rate in irradiated jawbone from 60% to 5%

  • TARDIVE DYSKINESIAS Tardive dyskinesia may complicate dental implant therapy.Alternatives to endosseous dental implants should be considered for patients with neurologic disorders including orofacial dyskinesia, trigeminal neuralgia, or orofacial dysesthesia.

Topic: Implants in patients with periodontitis

Authors: Ong, C et al:

Tittle:Systematic Review of Implant Outcomes in Treated Periodontitis Subjects.

Source: J Clin Periodontol 2008; 35:438

Type: Systematic Review

Rating: Good

Keywords:periimplantitis, failure

Purpose:To determine implant outcomes in partially dentate patients who have been treated for periodontitis compared with periodontally healthy patients.

Methods:

All longitudinal studies (until March 2006) of endosseous dental implants of at least 6 months of loading were searched. Studies presented with one or more of the outcome measures (implant survival, success, bone-level change, peri-implantitis) were included. Screening, data abstraction and quality assessment were conducted independently and in duplicate.

Results:

From 4448 citations, 546 full-text papers were screened and nine studies were included. Overall, the non-periodontitis patients demonstrated better outcomes than treated periodontitis patients. However, the strength of evidence showed that the studies included were at a medium to high risk of bias, with lack of appropriate reporting and analysis of outcomes plus lack of accounting for confounders, especially smoking. Furthermore, the studies showed variability in the definitions of treated and non-periodontitis, outcome criteria and quality of supportive periodontal therapy. Meta-analysis could not be performed due to heterogeneity of the chief study characteristics.

Conclusion:

There is some evidence that patients treated for periodontitis may experience more implant loss and complications around implantsthan non-periodontitis patients. Evidence is stronger for implant survival than implant success; methodological issues limit the potential to draw robust conclusions.

Topic:crestal bone height change

Authors:Rasperini G, Siciliano VI

Title:Crestal bone changes at teeth and implants in periodontally healthy and periodontally compromised patients. A 10-year comparative case-series study.

Source:J Periodontol. 2013 Nov 11.

Type:Comparative case-series

Rating:Good

Keywords:alveolar bone loss, peri-implantitis, periodontitis, smoking

Purpose:To compare the 10 year radiographic crestal bone changes around teeth and implants in periodontally compromised and periodontally healthy patients.

Methods:120 patients (60 with prev hx of perio, 60 healthy) were followed for 10 years post loading for radiographic crestal bone height of dental implants and adjacent teeth. 10 patients were smokers. Digital films were calibrated. Radiographic crestal bone change was calculated by subtracting the creatl BL at baseline from the crestal BL at the 10 year follow up.

Results:After 10 years, implant survival was 80-95% and 100% for teeth. In all categories evaluated, natural teeth were significantly more stable radiographically compared to implants. Adjacent teeth did not seem to be influenced by the presence or absence of bone loss ≥3mm at adjacent implants.

Conclusion:Long-term results show that natural teeth have greater survival and less marginal bone loss compared to dental implants. This was still true when looking at teeth with reduced periodontal attachment (treated and maintained). The decision to extract teeth in favor of dental implants should be carefully considered in partially edentulous patients.

Topic:Risk factors for implants

Authors: Klokkevold P, Han T

Title:How do smoking, diabetes and periodontits affect outcomes of implant treatment?

Source:Int J Oral Maxillofac Implants. 2007; 22 (suppl)173-202

Type:Review

Rating: Good

Keywords:dental implants, dental implant survival, diabetes, periodontitis, smoking, tobacco

Purpose: To evaluate the available literature to assess whether smoking, diabetes, and periodontitis have an adverse effect on the outcomes of implants placed in patients with these conditions.

Method: The dental literature was searched using the MEDLINE, Cochrane Collaboration, and EMBASE databases. Using specific inclusion and exclusion criteria, 2 reviewers evaluated titles, abstracts, and full articles to identify articles relevant to this review. All searches were conducted for articles published through May 2005. Data from included articles for each of the risk factor groups, smoking, diabetes, and periodontitis, were abstracted and analyzed.

Results: A detailed search of the literature and evaluation of relevant articles identified 35 articles for inclusion in this systematic review. Nineteen articles were identified for smoking, 4 articles were identified for diabetes, and 13 articles were identified for periodontitis. One article met the criteria for both smoking and periodontitis. Implant survival and success rates were reported for smokers versus nonsmokers; diabetic patients versus nondiabetic patients; and patients with a history of treated periodontitis versus patients with no history of periodontitis. The findings revealed statistically significant differences in survival and success rates for smokers (better for nonsmokers), with greater differences observed when the data were analyzed according to bone quality (less for loose trabecular bone). No difference in implant survival rate was found between patients with and without diabetes. Likewise, no difference in implant survival rates was found between patients with a history of treated periodontitis compared to patients with no history of periodontitis.

Conclusion: The results of this systematic review of the literature demonstrated that smoking has an adverse effect on implant survival and success. The effect of smoking on implant survival appeared to be more pronounced in areas of loose trabecular bone. Type 2 diabetes may have an adverse effect on implant survival rates, but the limited number of studies included in this review do not permit a definitive conclusion. A history of treated periodontitis does not appear to adversely affect implant survival rates but it may have a negative influence on implant success rates, particularly over longer periods.

Topic:Diabetes

Author:Dowel, S et al

Title:Implant success in people with type 2 diabetes mellitus with varying glycemic control. A pilot study.

Source:JADA: 138:2007:355-361

Type:Cohort study

Rating:Good

Keywords:Diabetes, dental implants, implant success

Purpose:The authors conducted a prospective cohort study to explore the relationship between implant success and glycemic control in patients with type 2 diabetes mellitus.

Methods:The authors used a two-phased enrollment, stratified by glycated hemoglobin (HbA1c) levels, to evaluate 50 implants in 35 subjects. The authors assessed nonsubmerged, nonrestored implants after placement, during healing and at abutment placement (35 newton centimeters) for restoration after four months. Outcomes assessed included implant success or failure, clinical complications and adverse events.

Results:The HbA1c levels of the subjects ranged from 4.5 to 13.8 percent. All 50 implants were integrated clinically. The authors identified three minor complications in three patients having HbA1c levels ranging from 7.4 to 8.3 percent. None of these complications affected the clinical management of the cases, and the authors did not identify any adverse events.

Conclusion:There was no evidence of diminished clinical success or significant early healing complications associated with implant therapy based on the glycemic control levels of subjects with type 2 diabetes mellitus. These findings support the continued investigation of the effects of glycemic control on implant therapy toward the development of therapeutic guidelines that will optimize implant therapy in patients with diabetes.

Topic:smoking and implant

Authors:Strietzel FP, Reichart PA, et al.

Title: Smoking interferes with the prognosis of dental implant treatment: a systematic review and meta-analysis.

Source:J Clin Periodontol. 2007 Jun;34(6):523-44. Review.

Type: Retrospective Study

Rating: Good

Keywords:dental implants; meta-analysis;odds ratio; smoking; success rate; survival rate

P: To investigate if smoking interferes with the prognosis of implants with and without accompanying augmentation procedures compared with non-smokers.

M&M:A systematic electronic and handsearch (1989 and 2005; English and German language; search terms “dental or oral implants and smoking”; “dental or oral implants and tobacco”) was performed to identify publications providing numbers of failed implants, related to the numbers of smokers and non-smokers for meta-analysis. Publications providing statistically examined data of implant failures or biologic complications among smokers compared with non-smokers were included for systematic review.

R: Of 139 publications identified, 29 were considered for meta-analysis and 35 for systematic review. Meta-analysis revealed a significantly enhanced risk for implant failure among smokers [implant-related odds ratio (OR) 2.25, confidence interval (CI(95%)) 1.96-2.59; patient-related OR 2.64; CI(95%) 1.70-4.09] compared with non-smokers, and for smokers receiving implants with accompanying augmentation procedures (OR 3.61; CI(95%) 2.26-5.77, implant related). The systematic review indicated significantly enhanced risks of biologic complications among smokers. Five studies revealed no significant impact of smoking on prognosis of implants with particle-blasted, acid-etched or anodic oxidized surfaces.

C:Smoking is a significant risk factor for dental implant therapy and augmentation procedures accompanying implantations.

Topic:smoking and implant

Authors: Bain CA

Title:Implant installation in the smoking patient.

Source:Periodontol 2000. 2003;33:185-93.

Type:Review.

Rating: good

Keywords:implant, failure, smoking,

Purpose:to review the association between smoking and implant failure; potential mechanisms, and benefits of smoking cessation.

Discussion:

  • Effects of smoking on general health:smoking has been shown to affect health in many ways such as; cancers especially lung cancer, chronic lung disease, myocardial infarctions, strokes and ischemic heart disease. Research show that 50% of smokers die from a smoking related disease, and life expectancy of smokers is reduced by 7.5 years. Smoking also has been shown to have an adverse effect on bone density.

  • Effects of smoking on wound healing: smoking is a complicating factor in post-surgical wound healing. Smokers show less reduction in PD after SRP, poorer healing after mucogingival surgeries, less favorable healing following OFD, greater loss of bone height, reduction in post-ext socket fill and more painful ext socket. Smoking compromises healing of duodenal ulcers. Also, in a study about healing after orthopedic surgery, it was shown than there are more delayed union or non-unions in smokers.

  • Influence of smoking on the actions of polymorphonuclear leukocyte, macrophages, circulation and blood flow:Several studies have shown that smoking causes reduced phagocytosis, delayed margination and diapedesis as well as compromised aggregation and adhesion of leukocytes to the endothelium in venules and arteries. Peripheral endothelial dysfunction, vessel wall injury and capillary loss is common in smokers, also reactive hyperemia and sequestration of blood cells in the microcirculation. Coronary flow reserve is also decreases after smoking high-nicotine cigarettes.

  • Smoking and implant failure:

    • Smoking and particularly heavy smoking increases the failure rates for machined titanium implants, likely due to a compromise of the blood supply in bone during early healing

    • This increased failure rate clusters largely in the maxilla, with much smaller differences between smokers and non-smokers for implant in the mandible.

    • Smoking is associated with a particularly high failure rate for implants placed into grafted maxillary sinuses.Some operators may consider this to be too great a risk to take, if the patient is unable or unwilling to stop smoking.

  • What happens if the potential implant patient stops smoking:Smoking cessation has been demonstrated to improve success rates in machined implant patients. In fact, implant placement may well be an effective motivator in assisting a smoker with cessation.

  • Bone density, smoking and implant success: There appears to be a relationship between heavy smoking and reduced bone density. This is seen in various areas of medicine, as well as in implant surgery and might explain high failure rates in Type 4 bone

  • Do different materials and surfaces make a difference:There is early evidence that rough surface implants, prepared with a double acid etched technique, have a high success rate in smokers. With success rates around 10% better overall (98.7% vs. 88.7%) and 15% better in the maxilla (97.3% vs. 82.1%) than our original results with machined Branemark implants in smokers, these are at present considered to be the implant of choice in smokers who cannot or will not stop smoking for implant placement.

Topic:Oral Bisphosphonates

Author: Fugazzotto P

Title:Implant Placement with or without Simultaneous Tooth Extraction in Patients Taking Oral Bisphosphonates: Postoperative Healing, Early Follow up and Incidence of Complications in Two Private Practices

Source:J Periodontol 2007; 78:1664-1669

Type:Retrospective study

Rating: Good

Keywords:Bisphosphonates; dental implants; osteonecrosis

Purpose:The purpose of this article was to document the results of treatment of patients with a history of oral bisphosphonate therapy in two private periodontal practices.

Methods:61 female patients were treated in two private offices. All patients were receiving oral bisphosphonate therapy in the form of alendronate or risedronate, 35 or 70 mg/week. All these participants were treated with implant placement and restoration or tooth extraction, immediate placement, and restoration. These patients were then followed for 12 to 24 months after implant placement. The incidence of hard and soft tissue complications, including the development of osteonecrosis were noted.

Results:There were no reported cases of osteonecrosis immediately postoperatively during the follow-up period in any of the 61 patients. One patient demonstrated a small tissue dehiscence at the 1-week postoperative exam. No other complications occurred. All implants were functioning successfully by the Albrektsson criteria 12 to 24 months post-insertion.

Discussion: While the concern with BON is very much real with IV bisphosphonate. A history of oral bisphosphonate use for a mean period of 3.3 years was not found to be a contributing factor to the development of osteonecrosis following implant placement. Due to the size of the patient population, larger controlled studies and retrospective studies are needed.

Topic:Radiation

Authors: Colella, Cannavale, Pentenero, Gandolfo:

Title:Oral implants in radiated patients: A systematic review

Source:Int J Orla Maxillofac Implants 2007; 22(4):616-623

Type:Systematic review

Rating: Good

Keywords: Dental implants, oral cancer, radiation therapy

Purpose:To evaluate and compare the effects of pre- and post-implant radiation therapy. Incidence of implant failure was linked to multiple variables and assessed.

Methods:A thorough review of the relevant literature was performed. Studies were original studies based in humans from 1990- 2006. The man outcome considered was implant failure, defined as implant mobility, implant removal necessitated by progressive marginal bone loss or infection (biologic failure). Restorative status was not considered a determinate of success (sleeping implants were considered a positive outcome). Overall implant failure rate was compared for pre-implantation radiation therapy vs. post-implantation. Four variables were considered: implant location (maxilla vs. mandible), dose of radiation, delay from radiation to implant placement, and timing of implant failure.

Results:18 articles were considered eligible for inclusion in the review.Implant failure in post-implantation radiation therapy: 6 studies overall reported 124 implants with 4 failures (3.2%). Implant failure in pre-implantation radiation therapy: An overall failure rate of 5.4% was reported, which was not significantly different from post-implantation. 22/46 failures reported the cause of failure, with 9 due to lack of osseointegration, 12 due to marginal bone loss, and 1 due to biting trauma. Implant failure in the maxilla was 17.5% and 4.4% in the mandible, a difference that was significant. Vascularized free flaps were associated with the lowest rate of implant failure. Radiation dose: Radiation doses lower than 45 Gy were associated with the lowest rate of implant failure, with 5% being reported at higher doses. Delay of radiation treatment to implant placement: All implant failures occurred within 36 months after treatment. Timing of implant failure: No failures occurred within one month, 3.1% failed within the first month and 0.8% failed after 1 year.

Discussion:Based on this study, the timing of implant placement (pre- or post-therapy)is not linked to a significant difference in implant failure rate, however significantly better outcomes were noted in the mandible.

Topic:osteoporosis
Authors:Holahan, C et al
Title:Effect of osteoporotic status on the survival of titanium dental implants.

Source: Int J Oral Maxillofac Implants. 2008:Sep-Oct; 23(5)905-10

Type:

Rating: Good

Keywords: dental implants, implant survival, osteoporosis

Purpose:Primary Objective is to perform a retrospective chart review to determine the effect of osteoporotic status on survival of dental implants in postmenopausal women. Secondary Objectives included assessing the effects of smoking status, age, and arch location on implant survival as a function of osteoporotic status.

Method: a retrospective chart review was completed on all women who were 50 years of age or older at the time of dental implant placement at the Mayo Clinic between Oct 1, 1983 and Dec 31, 2004. The medical and dental charts were evaluated to collect the following:

  1. BMD T-score within 3 years of implant placement

  2. Osteoporotic diagnosis based on BMD T-score

  3. Arch location of the implants

  4. Smoking status at time of implant placement

  5. Any implant failures (implant removal due to any reason other than infection or manufacturing defects)

The review resulted in 192 patients (646 implants). Implant survival was estimated using the Kaplan-Meier method. Follow up duration was calculated from date of implant placement to date of failure or last follow up.

Results:

  • The Kaplan-Meier t- and 10-year survival rates for the 64 implants in 192 patients were 93.8% and 92.5% respectively. The mean follow up was 5.4 years (range 11 days to 20.4 years). Mean age of women studied was 63.4 years (range 50.3 to 84.9 years)

  • Osteoporotic diagnosis of patients based on BMD T-score was: 49% diagnosed as non-OP, 29.7% had osteopenia and 21.4% had osteoporosis. 37 implant failures were found: 10 implant failures in the osteoporosis group, 10 implant failures in the osteopenia group and the other 17 failures occurred in patients with non-OP diagnosis.

  • No significant association between arch location and implant failure was identified.

  • 12.5% of patients were smoking at the time of implant placement. Smoking had a significant effect on implant failure. Implants in smokers were 2.6 times more likely to fail (5- and 10- year implant survival rate for smokers was 87.3%). Non-smokers had 94.6% and 93.1% survival rates.

Conclusion:

  • Dental implant survival rates in this group of patients were encouraging with a 10-year survival rate of 92.5%.

  • Implants placed in smokers were 2.6 times more likely to fail than those placed in nonsmokers. The difference between those were most evident in the first year after implant placement.

  • A diagnosis of osteoporosis or osteopenia is not a contraindication to dental implant therapy.

Topic: Biological Principles

Authors:Claudy et al

Title:Time interval after radiotherapy and dental implant failure: systematic review of observational studies and meta-analysis

Source:Clinical implant dentistry 2013;1-10

Type:Systematic Review

Rating:Good

Keywords:dental implants, meta-analysis, osseointegration, osteoradionecrosis, radiotherapy

Purpose: To compare the risk of failure of dental implants placed within 6 and 12 months after the end of radiotherapy versus the risk of those implants placed after 12 months from the end of radiotherapy.

Materials and method

Four electronic databases were searched for articles published until February 2013 without language restriction: Lilacs, Medline, Scopus and the Cochrane Central Register of Controlled Trials. Two reviewers independently assessed the eligibility criteria and extracted data. Meta-analysis was performed.

Results:Overall 3,749 observational studies were identified. After the screening of titles and abstracts, 236 publications were selected, and finally 10 articles were included in the analysis. The Relative Risk of failure (1.34) was higher in individuals who had dental implants installed between 6 and 12 months after receiving radiotherapy.

Discussion:The main finding was that placement of dental implants between 6 and 12 months postradiotherapy was associated with 34% higher risk of failure. This is statistically significant and clinically relevant. Literature suggests that patients treated with radiation doses exceeding 50 Gray Units (Gy) are at increased risk of failure of osseointegration because of the loss of ability to repair and neovascularize the irradiated bone. Hyperbaric Oxygen therapy (HBO) reduces the risk of failure of the implant because it increases the number of capillaries and fibroblasts. However, this was not observed in this review which agrees with results of Esposito who found that HBO is not essential.

Conclusion:

Minimum waiting period of 6 months postradiotherapy prior to dental implant placement is unlikely to be the most suitable, and healing periods with duration over 1 year may be beneficial.

Topic:prophylactic antibiotics

Authors:Sharaf B, Dodson TB.

Title:Does the use of prophylactic antibiotics decrease implant failure?

Source:Oral Maxillofac Surg Clin North Am. 2011 Nov;23(4):547-50

Type:literature review

Rating:high quality evidence used

Keywords: antibiotic use, implant failure

Background:Despite the high success rate, implant failures do occur. Failure can attributable to implant-related, patient-related, and surgical technique-related factors. Bacterial colonization of the implant surface and surgical site infection have be implicated in early implant failure. Once an infection ensues at the implant site, its eradication is usually difficult, and may lead to removal of the implant. For this reason, various regimens have been suggested to minimize early infections after implant placement. However routine use of antibiotics is not without risk.

Purpose: to answer the question, “in patients receiving dental implants, does the administration of prophylactic antibiotics reduce early implant failure?”

Materials and Methods:The authors searched using the following Medical Subject Headings (MeSH): antimicrobial agents, antibiotics or prophylactic antibiotics, and dental implants. Inclusion criteria:1) randomized controlled clinical trials, (2) meta-analysis or systematic review. The primary predictor variable was antibiotic therapy, classified as a preoperative dose of antibiotics, preoperative and postoperative antibiotic treatment, and no antibiotics. The primary outcome variable was implant failure. The secondary outcome variable was post- operative infection. Each article was reviewed and data summarized for the following variables: sample size, antibiotic use, implant failure, and postoperative infections. The treatment effect was measured using absolute risk reduction (ARR), which is defined as the absolute difference in failure rates between the intervention and control groups. The number needed to treat (NNT), calculated as the reciprocal of ARR, is defined as the number of implants that must be placed with antibiotic use to prevent 1 implant failure. Five articles were selected for review.Four studies were randomized controlled trials.

 

Results:a meta-analysis of the 4 RCTs included 1007 patients receiving a total of 2020 implants showed more implant failures in the groups not receiving antibiotics, with a statistically significant difference. The number of patients that needed to be treated with antibiotics to prevent 1 patient from having implant failure was 33.

Bottom Line: in the authors opinion, based on their review – significant reduction in implant failure was observed when patients received 2g Amoxicillin 1 hr preoperatively or 1 g amoxicillin 1 hr preoperatively followed by 500mg 4 times daily for 2 days postoperatively.

Critique:There are some drawbacks to the RCTs reviewed. The follow-up time varied from 3 months in 1 trialand 4 months in 2 trials to 5 months in 1 trial.Decreasing the follow-up period may decrease the number of failed implants and may overestimate the effect of antibiotics on the primary outcome variable: implant failure. Another drawback is the use of bone substitutes and other bone-regenerative procedures at the time of implant placement, which may affect implant healing and failure rates. The use of bone-regenerative procedures was reported in 2 studies.In addition, the effect of timing of implant placement (delayed or immediately after extraction) may potentially increase implant failure rates. Esposito and colleaguesdemonstrated in a logistic regression analysis that patients in the RCT who received immediate post-extraction implants had a 9% failure rate versus 2% in the delayed group, regardless of antibiotic use (P<.001).

Topic:Antibiotics

Author: Ahmad N, Saad N.

Title:Effects of antibiotics on dental implants: a review.

Source:J Clin Med Res. 2012 Feb;4(1):1-6.

Type:Systematic review

Rating: Good

Keywords:antibiotic, success rate, dental implants.

Purpose:to review the current literature and information on dental implants and prophylaxis. Our objectives are to ask whether or not antibiotics are beneficial to implants, and in what instances pre- and/or postoperative antibiotic regimes should be prescribed.

Material and methods: The systematic literature review was completed using the electronic databases, Pubmed, Medpilot and Medline. Retrospective or prospective controlled studies which met the inclusion criterion, were English studies conducted between 1955 to January 2009. Administrations of various prophylactic antibiotics regimens were accepted. An unsuccessful dental implant was characterized by any implant which failed within the first 3 months, and studies with follow ups within the first 5 months were included. Studies with loading were not included and only studies using low risk patients were included.

Results:Out of 853 studies, only 6 studies were included in this systematic review that met the criteria. 11406 implants used in this literature review, cases with no antibiotics had a 92 % success rate, cases with pre-op antibiotic alone had a 96% success rate, cases with post-op antibiotic alone had a 97% success

Conclusion:The cost-benefit ratio of any therapy, including all potential adverse effects, must be determined. The negative effects associated with use of antibiotic therapy must be assessed in comparison to the costs and morbidity related to treating infective endocarditis or infected prosthetic materials.

Critics:many studies were excluded because they did not include comparisons between no antibiotics, pre-op, post-op antibiotic use.

Topic: Antibiotics

Authors: Esposito M, Grusovin MG, Worthington HV

Tittle:Interventions for replacing missing teeth: antibiotics at dental implant placement to prevent complications.

Source: Cochrane Database Syst Rev. 2013 Jul 31;7:CD004152.

Type: Systematic Review

Rating: Good

Keywords:antibiotics, failure, survival

Purpose:To assess the beneficial or harmful effects of systemic prophylactic antibiotics at dental implant placement versus no antibiotic or placebo administration and, if antibiotics are beneficial, to determine which type, dosage and duration is the most effective.

Methods:

Cochrane Oral Health Group’s Trials Register (to 17 June 2013), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 5), MEDLINE via OVID (1946 to 17 June 2013) and EMBASE via OVID (1980 to 17 June 2013). Selection criteria: RCTs with a follow-up of at least three months, that compared the administration of various prophylactic antibiotic regimens versus no antibiotics to people undergoing dental implant placement. Outcome measures included prosthesis failures, implant failures, postoperative infections and adverse events.

Results:

Six RCTs with 1162 participants were included:

  • 3 trials compared 2 g of preoperative amoxicillin versus placebo (927 participants)

  • 1 compared 3 g of preoperative amoxicillin versus placebo (55 participants),

  • 1 compared 1 g of preoperative amoxicillin plus 500 mg four times a day for two days versus no antibiotics (80 participants), and

  • 1 compared four groups: (1) 2 g of preoperative amoxicillin; (2) 2 g of preoperative amoxicillin plus 1 g twice a day for seven days; (3) 1 g of postoperative amoxicillin twice a day for seven days, and (4) no antibiotics (100 participants).

  • The overall evidence was considered to be of moderate quality.

  • The meta- analyses of the six trials showed a statistically significant higher number of participants experiencing implant failures in the group not receiving antibiotics. The number needed to treat for one additional beneficial outcome (NNTB) to prevent one person having an implant failure is 25, based on an implant failure rate of 6% in participants not receiving antibiotics. There was borderline statistical significance for prosthesis failures, with no statistically significant differences for infections, or adverse events. No conclusive information can be derived from the only trial that compared three different durations of antibiotic prophylaxis since no event (implant/prosthesis failures, infections or adverse events) occurred in any of the 25 participants included in each study group.

Conclusion:

Scientific evidence suggests that antibiotics are beneficial for reducing failure of dental implants. Specifically 2 g or 3 g of amoxicillin given orally, as a single administration, one hour preoperatively significantly reduces failure of dental implants. It might be sensible to suggest the use of a single dose of 2 g prophylactic amoxicillin prior to dental implant placement. It is still unknown whether postoperative antibiotics are beneficial, and which antibiotic is the most effective.

Topic:antibiotics and implant failures/infections

Authors:Ata-Ali J, Ata-Ali F, Ata-Ali F.

Title:Do antibiotics decrease implant failure and postoperative infections? A systematic review and meta-analysis.

Source:Int J Oral Maxillofac Surg. 2013 Jun 25.

Type:Systematic review and meta-analysis

Rating:Good

Keywords:dental implants, infection, disease, antibiotic, meta-analysis, implant surgery

Purpose:To systematically review and perform a meta-analysis to determine does the use of antibiotics reduce the frequency of implant failure and postoperative infection.

Methods:A manual and PubMed electronic search was conducted for RCTs that met the inclusion criteria with a control group that did not receive antibiotics. Four RCTs were included in the final review.

Results:Four RCTs included had a total of 2063 implants in a total of 1002 patients. Antibiotic use significantly lowered implant failure rate with an OR 0.331. One needs to treat 48 patients in order to prevent one patient from having an implant failure. In contrast, antibiotic use did not significantly reduce the incidence of post op infection. The meta-analysis found that there is evidence in favor of systemic antibiotic use in patients receiving dental implants.

Conclusion:

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22. Pathogenesis / Disease Activity: Pathogenesis and Inflammation

 HOME PERIO TOPICS 

Provide an overview of the pathogenesis of periodontitis. Describe the sequence of events in order of occurrence.

  1. Listgarten M. A. Nature of periodontal disease: Pathogenic mechanisms. J Periodontal Res. 1987; 22: 172-78

  2. Schroeder H: Discussion: Pathogenesis of periodontitis. J. Clin. Periodontol. 13:426-430, 1986. (Review)

  3. PAGE R & K. KORNMAN: The pathogenesis of human periodontitis: an introduction. Periodontology 2004 Vol. 14, 1997, 9-11

  4. KORNMAN K,R. PAGE & M. TONETTI: The host response to the microbial challenge in periodontitis: assembling the players. Periodontology 2000, Vol. 14, 1997, 33-53

  5. Kinane DF: Causation and pathogenesis of periodontal disease. Periodontol 2000. 25:8-20,2001 (Review)

  6. DARVEAAUN R, NET ANNER& ROYC . PAGE: The ,microbial challenge in periodontitis. Periodontology 2000, Vol. 14, 1997, 12-32

  7. PAGE R, S. OFFENBACHER, SCHROEDER, G. SEYMOUR & K. KORNMAN: Advances in the pathogenesis of periodontitis: summary of developments, clinical implications and future directions. Periodontology 2OW. Vol. 14, 1997, 216-248

Describe Page & Schroeder’s model in detail.

  1. Page RC, Schroeder HE: Pathogenesis of inflammatory periodontal disease. A summary of current work. Lab. Invest. 34:235-249, 1976 (Review)

Discuss Gingivitis

  1. Van Dyke TE, Offenbacher S, et al. What is gingivitis? Current understanding of prevention, treatment, measurement, pathogenesis and relation to periodontics. J Int Acad Perio 1:3-15; 1999. (Review).

  2. Page RC. Gingivitis. J. Clin. Periodontol. 13:345-355, 1986. (Review)

Does all gingivitis become periodontitis? Is gingivitis a prerequisite for periodontitis?

  1. Schroeder HE, Lindhe J : Conversion of stable established gingivitis in the dog into destructive periodontitis. Arch. Oral. Biol. 20:775-782, 1975.

  2. Soames JV, Entwisle DM, Davies RM : The progression of gingivitis to periodontitis in the beagle dog. A histologic and morphometric investigation. J. Periodontol. 47:435-439, 1976.

How do periodontal pockets form? Which tissues are destroyed first?

  1. Ritchey B, Orban B. The periodontal pocket. J. Periodontol. 23:199-213,1952.

  2. Takata T, Donath K : The mechanism of pocket formation – A light microscopic study of undecalcified human material. J. Periodontol. 59:215-221, 1988.

  3. Saglie, Carranza, Newman and Pattison: Scanning electron microscopy of the gingival wall of deep periodontal pockets in humans. J Periodontal Res. 1982; 17: 284-293

List enzymes implicated in periodontal destruction and their origin. Do these enzymes have any therapeutic or diagnostic significance?

  1. REYNOLDS J & MURRAYC . MEIKLE: Mechanisms of connective tissue matrix destruction in periodontitis. Periodontology 2000, Vol. 14, 1997,144-157

  2. Van der Zee E, Everts V, Beertsen W: Cytokines modulate routes of collagen breakdown. J Clin Periodontol. 24:297-305, 1997.

  3. Lee W, et al. Evidence of a direct relationship between neutrophil collagenase activity and periodontal tissue destruction in vivo: Role of active enzyme in human periodontitis. J Periodont Res 1995; 30:23-33

  4. SCHWARTZ, Z., J. GOULTSCHIN D. DEAN & B. BOYAN: Mechanisms of alveolar bone destruction in periodontitis. Periodontology 2000, Vol. 14, 1997, 158.1 72

  5. Mogi M, J. Otogoto, N. Ota and A. Togari: Differential Expression of RANKL and Osteoprotegerin in Gingival Crevicular Fluid of Patients with periodontitis. J DENT RES 2004 83: 166

  6. Nonnenmacher C, K. Helms, M. Bacher, R.M. Nüsing, C. Susin, R. Mutters, L. Flores-de-Jacoby and R. Mengel: Effect of Age on Gingival Crevicular Fluid Concentrations of MIF and PGE2. J DENT RES 2009 88: 639

  7. Johnson RB, Serio FG, Dai X: Vascular endothelial growth factors and progression of periodontal diseases. J Periodontol 70:848-852, 1999

How can the host response be modified as a part of periodontal therapy?

  1. Salvi GE, Lang NP. Host response modulation in the management of periodontal diseases. J Clin Peridontol 2005; 32 (Suppl. 6): 108–129.

  2. Bhatavadekar NB, Williams RC. Commentary: new directions in host modulation for the management of periodontal disease. J Clin Periodontol 2009; 36: 124–126


Provide an overview of the pathogenesis of periodontitis. Describe the sequence of events in order of occurrence.

Topic: Nature of periodontal disease

Authors: Listgarten M.

Title: A. Nature of periodontal disease: Pathogenic mechanisms.

Source: J Periodontal Res. 1987; 22: 172-78

Type: Discussion

Rating: Good                                                               ARTICLE

P: Discussion article on the nature of periodontal disease and pathogenic mechanisms.

D: The oral microbiota, one of the most complex in the body, comprises over 300 species. Of these, about 30 are routinely observed and account for the majority of the cultivable strains. Health of periodontal tissues is maintained in a relatively stable state through the establishment of host-parasite equilibrium compatible with minimal tissue destruction and ready replacement or repair of damaged structures. Alterations in this equilibrium may develop as a result of local or systemic changes that decrease host resistance or from qualitative/quantitative alterations of periodontal microbes which result in increased virulence. These upsets may account for “bursts of disease activity. Bacteria can contribute to periodontal disease by direct injury of the host tissues (toxins, enzymes, toxic metabolic end products) or they can also act indirectly by triggering host mediated responses that may result in self-injury.

Role of bacteria and host-mediated tissue injury is discussed in detail.

Bacteria

  • Non-specific theory of plaque induced periodontal disease (Loesche): Sheer mass of microorganisms (MOs) generate sufficient noxious stimuli to induce inflammatory response in host. Seen in gingivitis.

  • Certain forms of periodontal disease (AgP) caused by particular organisms which cause disease by various mechanisms

Direct toxicity: Variety of substances of bacterial origin which are capable of causing injury. They are usually of large molecular weight and may include some enzymes. Classically toxins have been divided in endotoxins and exotoxins.

  • Exotoxins: proteins released by live microorganisms into their immediate environment where they can cause direct tissue injury. Some exotoxins have a specific affinity for certain cell types. Neurotoxins for nerve tissue, leukotoxins for neutrophils or epitheliotoxins for epithelial cells.

Leukotoxin

  • produced by Aa , associated with outer membrane of A.a cell wall from which it may be shed as membranous vesicles

  • shown to have correlation with periodontal disease.

  • shown to readily lyse human PMNs (Brehni et al)

  • able to kill human monocytes and weaken local host defense (Taichman et al)

Endotoxins: Lipopolysacchirides (LPS) which are structural components of Gram (-) bacteria. Their release occurs primarily after lysis of the cells. Endotoxins can exert a wide diversity of biological events, yet they share a common molecular structure. The linear molecule which is oriented perpendicularly to the bacterial cell surface consists of 3 distinct regions.

  1. Lipid A region which forms part of the outer half of the outer membrane of the cell wall. It is responsible for direct toxicity.

  2. Thecentrally located core polysaccharide

  3. The polysaccharide side chains, where the 0-somatic antigensreside, extend peripherally beyond the outer membrane.

The carbohydrate components provide the lipid A with hydrophilic properties, which enhance its pathogenicity and may increase the resistance of the bacteria to phagocytosis.

Endotoxins:

  • Enhance bone resorbing quality of osteoclasts

  • They can also bind to surface of PMNs or macrophages which internalize the endotoxin. Subsequent internalization of the endotoxin causes the cells to release their lysosomal enzymes extracellularly, with resulting damage to the local tissues and the generation of peptides that are vasoactive and chemotactic for PMNs.

  • Activate complement through the indirect pathway, with the consequent generation of complement-derived mediators of inflammation.

  • Act as modulators of bacterial cell uptake by phagocytic cells, with the endotoxin able to promote or inhibit phagocytosis depending on concentration.

  • Interfere with new attachment to denuded root surfaces.

Enzymes: Bacteria may exert pathogenicity in part through tissue invasion. Assorted enzymes may facilitate bacterial tissue penetration by removing various structural barriers and destroying host proteins that play a key role in host defenses like IgG’s.

  • Proteases, specifically collagenase, hyaluronidase, and chondroitin sulfatase are of particular interest in periodontal disease. They can be found in spirochetes and black pigmented bacteroides.

  • Metabolic products: End products of bacterial metabolism e.g. ammonia, indole, hydrogen sulfide, fatty acids also contribute to initiation and disease progression. Local changes in pH due to metabolism may also affect survival of certain microorganisms.

Indirect toxicity:

Effect on host cells: Bacterial enzymes may play an important role in neutralizing some of the oxygen -dependent antibacterial host defenses. Alterations in tissue oxygen levels may also favor the establishment of anaerobic infections that are associated with periodontitis. Bacterial protease can contribute to indirect injury of the host by destroying the functional activity of humoral antibodies directed against bacterial antigens.

Effect on bacterial cells: Bacterial interactions may play an important role in controlling the ability of microorganisms to colonize the tissues.

Host-mediated tissue injury

  • Caused by inflammation by triggering variety of injurious stimuli including thermal, mechanical, chemical trauma

  • Complement activation (IgG and IgM react with assorted bacterial antigens to form insoluable complexes). The formation of insoluble antigen- antibody complexes can activate the complement cascade with the resulting release of a number of mediators of inflammation into the extracellular environment. These can contribute to the influx of PMNs, the generation of additional vasoactive molecules and the outpouring of hydrolytic enzymes of lysosomal origin into the extracellular environment.

  • The lipoteichoic acid and lipopolysaccharides of the gram-negative cell wall are able to activate the complement cascade through the alternative pathway. While activation of complement has an overall beneficial effect in proecting the host against bacterial attack, some tissue destruction is unavoidable. Tissue injury is due in part to the complement-mediated influx of phagocytic cells and the release of lysosomal enzymes, and the production, by lymphocytes and macrophages, of assorted lymphokines that are able to kill cells and resorb bone.

Topic: Pathogenesis

Authors: Schroeder H

Title:Discussion: Pathogenesis of periodontitis.

Source: J. Clin. Periodontol.13:426-430, 1986.

Type: Review

Rating: Good                                                              ARTICLE

Keywords: Pathogenesis, periodontitis

Purpose: Discussion on the pathogenesis of periodontitis

Discussion:

  • Periodontitis is a local infectious disease caused and chronically maintained by a mixed, predominantly anaerobic bacterial infection of the subgingival portions of the periodontium. There are several difficulties in attempting to classify periodontal disease.

  • Author suggests the use of gingival pocket depth as a diagnostic criterion because it is the precursor of periodontal pocket. A gingival pocket is a shallow pocket (1-2mm) and histopathologically is similar to the periodontal pocket. No doubt that the development of gingival pockets is due to bacterial plaque extending apically along root surface. Once a gingival pocket has formed, gingivitis is no longer reversible with simple reestablishment of OH. Any pocket lined with pocket epithelium presents a pathophysiologic situation of associated with high tissue permeabilityincreased tissue reactivityinfected w/ subgingival bacteriaunattainable to remove w/ OH.

  • Transition from a gingival to a periodontal pocket is also due to the host response. There is no spontaneous shift back from the established lesion to the early.

  • The width and shape of infrabony pocket is also important and should be assessed radiographically.

  • Bone resorption occurs when plaque approaches 0.5 to 2.5 mm to the bone.Large bowel – shaped defects associated with periodontal pockets but extending further than the plaque radius, are probably related to lateral invasion of the soft tissues with plaque.

  • BOP is useful only for the early stages of gingivitis since evaluating it is subjective with regard to severity.

BL:The diagnosis and the pathogenesis of a particular patient with periodontitis are usually unknown. Factors other than bacteria may influence the pathogenesis of periodontitis, like OH, food impaction, iatrogenic factors, all of which interfere with the host-parasite relationship

Topic:Pathogenesis

Authors:Page R, Kornman K

Title:The pathogenesis of human periodontitis: an introduction
Source: Periodontology 2000 Vol. 14, 1997, 9-11

Type:Review

Rating:Good                                                               ARTICLE

Keywords:pathogenesis

Review:The major developments since the 1976 article by Page & Schroeder have been the discovery of the pathways through which bacteria activate host cells and systems in a manner that tissue destruction ensues and elucidation of the pathways through which the extracellular matrix components of the gingival and periodontal ligament are destroyed and alveolar bone is resorbed. Based on the current understanding, evidence is now sufficient for the development and application of new preventive measures, diagnostics and treatments targeted at blocking or altering these pathways.

Conclusion:Periodontitis is not a single homogenous disease but rather consists of a family of closely related diseases each of which may vary somewhat in etiology, natural history and response to therapy. There is a common chain of events of pathogenesis that is influenced by other factors including genetic and other risk factors may differ from one form of disease to another. Antigens and various other virulence factors, and in some cases invading bacteria, comprise the microbial challenge, and the host responds with an immediate inflammatory andimmune response that can influence the challenge. The host response results in production of cytokines, eicosanoids, other inflammatory mediators such as the kinins, complement activation products and matrix metalloproteinases, which perpetuate the response and mediate connective tissue and bone destruction. All of these events are influenced by disease modifiers, both genetic and environmental or acquired. The clinical picture observed is a result of the sum of these events. The severity and rate of progression of disease feedback to influence the nature and magnitude of the microbial challenge by, for example, influencing the pH and availability of oxygen and various nutrients in the periodontal pocket.

Topic:Pathogenesis

Authors: Kornman KS, Page RC, Tonetti MS.

Title:The host response to the microbial challenge in periodontitis: assembling the players.

Source:Periodontol 2000. 1997 Jun;14:33-53.

Type:Review

Rating: Good                                                              ARTICLE

Keywords:pathogenesis, host response

Purpose:To describe the histologic, cellular and molecular changes that occur during the transition from health to disease initiation and progression.

Discussion:Periodontitis is an infectious disease process. Bacteria and their products interact with the junctional epithelium and penetrate into the underlying connective tissue. Inflammation is caused and leukocytes (especially neutrophils) exit the post-capillary venules and end up in the sulcus. Collagen and other components of extracellular matrix are destroyed. Supra-g plaque extends apically and into the gingival sulcus, cells of JE are stimulated to proliferate and a gingival pocket is formed. At an early stage there is an enlarging leukocyte infiltrate and subsequently the lesion becomes dominated by B-cells that produce antibodies. As the disease worsens, periodontal pockets deepen, the components of the extracellular matrix of the gingiva and PDL are destroyed and alveolar bone is resorbed.

Scene 1. Acute bacterial challenge phase: the epithelial and vascular elements respond to the bacterial challenge.

Epithelial membranes, flushing by saliva and GCF protect the tissues from initial bacterial invasion. High turnover rate of epithelium is associated with rapid replacement of damaged cells.

When bacteria start to accumulate the release metabolic products (including fatty acids and the lipopolysaccharides (LPS) of Gram- bacteria) that activate JE cells to release various inflammatory mediators such as IL-8, IL-1αPG-E2, MMPs, TNF. Neural components of the epithelium influence the local vascular response. The bacterial products and epithelial response activate mast cells to release histamine and activate vascular endothelial cells to release IL-8 within the vessels to assist in localizing neutrophils.

Scene 2. Acute inflammatory response phase: the tissues respond to the early signals.

The wide extracellular spaces oh the JE allow neutrophil migration. The vascular leakage and activation of serum proteins such as complement, begin to amplify the local inflammatory response and produce further endothelial cell activation. Leukocytes and monocytes are recruited. Neutrophils exit the inflamed vessels and form a wall between plaque and gingival tissues. They are capable of killing bacteria by phagocytosis and prevent extension apical and lateral extension of plaque. PMNs are the majority of cells in the sulcus and mononuclear cells the majority of tissue infiltrate. IL-8 appears to be critically involved in PMN recruitment.

Macrophages produce mediators of the immune and inflammatory responses including IL-1β, IL-1 receptor antagonist, IL-6, IL-10, IL-12, TNF, IFN, MMPs, PG-E2 and chemotactic substances such as monocyte chemoattractant protein (MCP) and macrophage inflammatory protein (MIP).

Scene 3. Immune response phase: activation of mononuclear cells shapes the local and systemic immune response.

The changes in this phase are associated with periodontal pocket. Soon after inflammation starts the exudate from the vessels becomes predominated by mononuclear cells. T-cells, B-cells and plasma cells become evident in the tissues. T-cells produce IL-2, 3, 4, 5, 6, 10 and 13, TNF-IFN, TGFand chemotactic substances. Plasma cells become prominent in the tissues and produce immunoglobulins such as IgG, IL-6 and TNF-Fibroblasts are also activated and produce MMPs and tissue inhibitor of matrix metalloproteinases (TIMPs). Macrophages become effector cells and depending on the nature of the challenge secrete a restricted set of cytokines and express surface receptors that influence the antigen specific immune response that directly targets the pathogen. Their products alter the local environment in several ways. They produce chemokines that recruit additional monocytes and lymphocytes, they favor collagen degradation (through the production of specific factors such as PGE2 and MMPs) and they activate CD4+ T-lymphocytes and to differentiate to cytokine producing T cells that help B cell differentiation and antibody production.

IL-1 is a major mediator in periodontitis. IL-1β comes mainly from activated macrophages and fibroblasts. IL-1α comes mainly from keratinocytes of the junctional or pocket epithelium. Production is induced by LPS, other bacterial components and by IL-1 which is autostimulatory. IL-1 upregulates complement Fc receptors on neutrophils and monocytic cells, and adhesion molecules on fibroblasts and leukocytes. It enhances production of MMPs and PGs by macrophages, fibroblasts and neutrophils. Finally, it upregulates major histocompatibility complex expression by B and T cells and facilitates their activation, expansion, and Ig production.

Scene 4. Regulation and resolution phase: determinants of protective components in the sulcus and collagen balance in the tissues.

This phase represents the initial loss of attachment. T-cells and macrophages are producing selective subsets of prostanoids and cytokines that favor net loss of collagen and bone and less effective antibody production. The inflammatory mediator load increases and includes contributions by the fibroblasts of interleukins (16, 8), PGE2, TNFa, collagen, MMPs and TIMPs. Plasma cells are prominent.

Topic:Review of Pathogenesis of Periodontal Disease          burst hypothesis             Article

Authors: Kinane D. et al

Title:Causation and pathogenesis of periodontal disease

Source:Periodontology 2000. 25:8-20,2001

Type:Review

Rating: Good                                                              ARTICLE

Keywords:Review, pathogenesis, periodontitis, gingivitis, microbiology

Purpose:To review the causation and pathogenesis of periodontal disease.

Discussion:

  • Gingivitis must precede periodontitis, however, not all gingivitis progresses to periodontitis. Periodontitis has subject and site predilection, is a continuous process that undergoes exacerbation periods (“burst hypothesis”).

  • Prevalence of periodontitis in the USA is 35% in adults (13% moderate to severe, 22% mild).

  • Even in clinically healthy gingiva neutrophils are found in the junctional epithelium, PMN’s are attracted to the area by bacterial products and epithelial cells proteins, but if they become overloaded, “degranulation” and tissue damage occurs from toxic enzymes.

  • Most individuals show signs of gingivitis 10-20 days after plaque accumulation

  • In gingivitis, capillary beds open, there is a transudate and influx of inflammatory cells (macrophages and neutrophils as phagocytic cells; lymphocytes as immune response-related cells).

  • Progression from gingivitis to periodontitis requires time, why some patients develop the periodontitis more readily than other is multifactorial including risk factors of particular bacterial species, age, socioeconomics and race, smoking, systemic disease, and genetics. Destructive processes are initiated by bacteria but propagated by host cells.

  • Microorganisms of normal flora are present in gingivitis while exogenous or usual anaerobic seem to be implicated in periodontitis.

                             The Classification of Kinane and Lindhe

Clinical condition

Histopathological condition

 Pristine gingiva

 Histological perfection (no inflammatory infiltrate)

 Normal healthy gingiva

 Initial lesion of Page and Schroeder (histologically has features of inflammatory infiltrate)

 Early gingivitis

 Early lesion of Page and Schroeder (lymphoid cells immediately below JE, loss of collagen)

 Established gingivitis

 Established lesion with no bone loss or apical epithelial migration

 Plasma cell density between 10-30% of leukocyte infiltrate

 Periodontitis

 Established lesion with bone loss and apical epithelial migration from the CEJ

 Plasma cell density > 50% (plasma cells predominance reflects bone loss)

Topic:Pathogenesis

Authors: DarveauRP et al

Title:The microbial challenge in periodontitis

Source:Periodontology 2000. 1997 Jun;14:12-32.

Type:Review

Rating: Good                                                              ARTICLE

Keywords:dental plaque, biofilm, P. gingivalis, calculus, plaque, innate host response

P: The article reviews the composition of dental plaque, the ability of the bacteria to develop strategies that help them survive in the oral environment and the host defense system that constantly monitors the bacterial colonization status and prevents bacterial invasion into the tissues.

D:

Biofilm: matrix-enclosed bacterial populations adherent to each other and/or to surfaces or interfaces.

Dental plaque formation: Microbial coating of a freshly cleaned tooth surface occurs rapidly. Two initial colonizers are Strep. GordoniiandA. naeslundii. Rapid colonization is favored by the ability of co-aggregation (two genetically distinct bacteria recognize and bind to each other; co-aggregation is based on the specific interaction of a proteinaceous adhesion produced by one bacterium and a respective carbohydrate or protein receptor found on the surface of another bacterium). Some bacteria can bind to each other without co-aggregation. Fusobacteriumspecies co-aggregate with all other oral bacteria, and thus play a major role to biofilm formation.

Dynamics of the dental plaque growth and host inhibition:

·     Dental plaque growth is favored by inter-species cooperation, GCF and biofilm formation (aqueous channels).

·     Host inhibition of supragingival plaque is mainly for the mechanical and anti-microbial properties of saliva. Subgingival plaque is inhibited by limited space and host innate defense system, which components are brought with the GCF.

·     Plaque doubling times are more rapid in early development and slower in more mature films.

·     Saliva:IgA, lactoferrin, lysozyme, peroxidase, antimicrobial proteins (histatins: antifungal and antibacterial activity)

·     GCF:contains nutrients for bacteria. However, also contains lysozyme, vascular permeability enhancers (bradykinin, thrombin, fibrinogen), antibodies, lymphocytes

Role of the dental plaque biofilm in periodontal disease:

·     Non-specific bacterial sheddingprobably represents the major mechanism by which the host is informed of the amount and type of bacterial colonization occurring on the biofilm.

·     Bacteria can have direct or indirect effects (indirect: bacteria activate one cell type which in turn activate another) on host cells.

·     Host cell response is grouped in myeloid (cytokine secretion) and non-myeloid (various inflammatory mediators).

·     The dental plaque biofilm microbial composition can influence innate host inflammatory surveillance. LPS is one of the most probable mechanisms by which the host can sense different biofilm bacteria. Biofilm composition may result in a destructive response.

·     The expression of bacterial virulence requires participation from the dental plaque biofilm. Host cell contact by pathogenic bacteria was shown to activate regions of the bacterial chromosome termed pathogenicity islands.

Potential role of P. gingivalis in periodontitis can be suppression of the innate host inflammatory response to bacteria.

LPS from this bacteria does not activate E-selectin, which would allow for vascular permeability of the endothelial cells for the PMNs to migrate and attack the bacteria.Pg has also shown to impair other bacteria from stimulation E-selectin expression. E-selectin can be activated indirectly by TNF-α and IL-β, however, PgLPS is a poor activator of these cytokines. This is in stark contrast to observations in clinical periodontitis of a large cellular inflammatory infiltrate and increased production of a variety of molecular mediators of inflammation.

·     A gradient of IL-8 expression exists in normal tissue to guide leukocytes to the site of bacterial colonization (in presence of P.g, epithelial cells lose their ability to secrete IL-8, rendering the host unable to locate the source of microbial colonization).

·     P.g is considered an opportunistic pathogen (may be a pathogen provided by the right combination of dental plaque).

·     Aa and Pg invade host cells, providing not only a source of potential re-infection after mechanical debridement, but also a more difficult situation for the host to recognize the bacterial challenge.

Biofilms and therapy:

·     Biofilms are notoriously resistant to surfactants and antibiotics as well as opsonization and complement –mediated phagocytosis and killing.

·     The release of membrane vesicles and cell wall fragments serve to protect bacteria in the biofilm by acting as decoys that bind innate host defense components.

·     The resistance of subgingival biofilms to normal host defenses has important consequences for the patient and for periodontal therapy. Physical removal is essential.

Microbial composition associated with different clinical states of periodontal health:

·     Gingival health: Mostly gram-positive, streptococci and actinomyces, with about 15% gram-negative rod species. Bacterial load is relatively low in gingival health. An individual is more likely to manifest gram-negative bacteria and perio pathogens in healthy sites with increasing age and periodontal disease history.

·     Gingivitis: Increased microbial load and a corresponding increase of gram-negative bacteria.

·     Periodontitis: Increased total microbial load. Elevated proportions of P.gT.f. and A.a. Elevated counts of the red and orange complex bacteria. Those species will determine the host response.

Clonal analysis has provided new insights into transmission and pathogenesis:

·     Molecular epidemiological tools have identified more intraspecies variation than previously thought (restriction endonucleases analysis, restriction fragment length polymorphism, ribotyping).

·     Transmission of periodontal bacteria occurs more likely through intimate contact, mostly within the family but not within general population communities (school, work environment)

·     Clonal type analysis is being used to determine the presence of different clonal types. Various clonal types of the same bacteria can be found within the same host. Very limited number of clonal types have been identified due to the magnitude of samples necessary to prove clonality.

·     The virulence of numerous clonal types is not clear.

Topic:pathogenesis of perio disease

Authors: Page R, Offenbacher S,

Title:Advances in the pathogenesis of periodontitis: summary of developments, clinical implications and future directions

Source:Periodontol 2000. 1997 Jun;14:216-48

Type:review

Rating: good                                                              ARTICLE

Keywords:periodontal pathogenesis, immune system, periodontitis

Purpose:To present the basic concepts and facts about pathogenesis of human periodontitis based on literature.

Discussion:

  • Periodontitis is a family of diseases that differ in etiology but have a common underlying chain of events. The severity and rate of progression of disease feedback to influence the nature and magnitude of the microbial challenge. Many modifying influences may affect the onset and progression of disease or the response to various kinds of therapy. These influences may last for life, or vary in magnitude of effect at different times.

  • Bacteria are essential but insufficient to cause disease, host factors are equally important. A.a. produces different clinical disease patterns in different people. This appear to be determined by combinations of factors like genetics and smoking.

  • P. gingivalis, A.a. and B. Forsythus cause most cases of periodontitis except for acute necrotizing periodontitis (ANP).

  • Subgingival microbial plaque behaves as biofilm. The behavior of the bacteria (mainly gram -) in it is different. They resist the host defense and also antibiotics. Physical disruption and removal are effective ways of dealing with biofilms.

  • Periodontitis enhances the risk for various systemic diseases, including atherosclerosis, coronary heart disease, stroke and infants with low birth weight.

  • Studies have shown that periodontopathic bacteria can be transmitted among individuals living in close contact.

  • P. gingivalis is special in that its lipopolysaccharide does not activate the expression of E-selectin in vascular endothelial cells (which then triggers binding of leukocytes) therefore blocking the local neutrophil response to itself and other microorganisms in the plaque.

  • The disease process is characterized by destructive periods followed by periods where this process subsides. There is experimented evidence that the responses in periodontal disease behave as if they occurred in a close system and many different balances can occur inside it through the biofilm/host interaction.

  • As the microbial challenge increases clinical signs of inflammation in the gingival margin begin. The junctional epithelium plays a key role, initiating vascular endothelial responses and neutrophils migrate to the sulcus. Macrophages, lymphocytes and plasma cells are the majority of cells in the tissues. If the bacteria are not eliminated inflammation worsens and connective tissue and bone are destroyed. In this procedure host cells, for example fibroblasts or epithelial cells, can be activated to produce prostaglandin E2and matrix metalloproteinases resulting in destruction of the components of the extracellular matrix. These cause apical extension of the epithelium and pocket formation. Rete pegs of junctional epithelium to the connective tissue are also formatted.

  • The stages of periodontitis according to its pathogenesis are initial, early, established and advanced lesions.

  • Several studies agree to the conclusion that bone absorption is observed in a 2.5mm range around bacteria, but Schroeder pointed out lesions much greater than 2.5mm around single teeth.

  • Thesusceptibility to periodontal disease differs between patients as some of them may only develop gingivitis whereas others with the same pathogens and comparable amounts of plaque may proceed to periodontitis, depending on several factors as the host’s response.

  • Cytokines belong to a large protein family that comprises the major regulators of the immunoinflammatory response in periodontitis. Interleukins and chemokines are subfamilies of the cytokines, while interferon – and TGF-also belong to the cytokines.

  • Both Th1 and Th2 clones of T helper cells can be met in periodontal lesions. The first one produces mostly interferon-γ and the second IL-6, IL-7 and IL-8. Whether any of these clones is associated with a specific clinical status is not yet clear.

  • Prostaglandins and leukotrienes are major initiators of inflammation and PGE2is the major mediator of pathological alveolar bone destruction. The progress of the disease is not on dimensional or unidirectional. It is constantly being adjusted as a result of multiple and changing microbial challenges and multiple local and systemic host defenses. Clinically periods of quiescence are followed by bursts of destructive disease activity. The mechanisms that force the transition from one condition to the other are not completely known. Bone absorption is a result of uncoupling the tightly coupled process of bone resorption and bone formation, and more significant after 25-30 years of age.

  • Periodontitis is a multifactorial disease. Bacteria are essential but insufficient to cause it. Several hereditary, host and other risk factors (such as diabetes mellitus, smoking, stress, HIV infection, socioeconomic factors, oral hygiene) coexist and modify the severity and type of the disease. Except for diabetes it is associated with major systemic diseases, such as cardiovascular disease and pre-term low birth weight delivery. Genetics has been shown to influence early onset periodontitis and adult forms. This influence is mediated through polymorphisms in the genes responsible for producing factors important in the pathogenesis of periodontitis (IL-1, IgG2m TNF-).

Describe Page & Schroeder’s model in detail.

Topic:Pathogenesis

Author:Page R., Schroeder H.

Title:Pathogenesis of Inflammatory Periodontal Disease: A Summary of Current Work

Source:Lab. Invest. 34:235-249, 1976

Type:Review

Rating: Good                                                              ARTICLE

Keywords:Gingivitis, Periodontitis, Chronic inflammation, Microbial plaque

Purpose: to discuss and review the current ant historic literature about the pathogenesis of periodontal disease

Discussion:Bacterial substances in plaque comprise the primary etiologic agent in gingivitis and periodontitis; however, many significant features of the disease cannot be accounted by this factor alone. There is a new belief that intrinsic host-related factors play an important role in the destructive process.

Historic Perspective

In the 18th and 19th centuries clinical observation was the predominant method used to understand the pathogenesis of the inflammatory periodontal lesion. In the late 19th century, there was a period of structural and morphologic analysis that began to examine the microscopic structures. During the past decade, the increased power of the electron microscope has provided additional insight into many of the cellular aspects and ultrastructural alterations.

Early concepts of pathogenesis

Gothieb (1946) presented the concept of “cementopathia”. He hypothesized that interference with continuous cementum deposits result in a lack of attachment of the collagen fibers of the gingiva and PDL. Goldman postulated an initial degenerative change in these fiber followed by epithelial cell proliferation and migration. Aisenberg (1948) showed that epithelial cells migrate apically between presumably normal connective tissue bundles. Cohen (1958), expressed the idea that the periodontal lesion may begin as a failure of the oral epithelium to replace the reduced enamel epithelium in the interproximal areas. James and Counsell (1927), and Fish (1935), introduced the zone of injury: Inflammatory cells accumulate in the JE and CT at the base of the sulcus. The zone of injury is located just coronal to the apical termination of the junctional epithelium.

Current view: the Page and Schroeder model.

Initial lesion (2-4 Days):

Lesion is localized to the gingival sulcus. The JE and most coronal portion of the CT are involved.

  1. Classic vasculitis of vessels subjacent to the JE

  2. Exudation of fluid from the gingival sulcus

  3. Increased migration of leukocytes (PMNs mainly) into the JE and gingival sulcus

  4. Presence of serum proteins, especially fibrin, extravascularly

  5. Alteration of the most coronal portion of the JE

  6. Portion of perivascular collagen disappears, and the resultant space is occupied by fluid, serum proteins (especially fibrin) and inflammatory cells.

Early Lesion (4-7 days):

  1. Presence and accentuation of the features described for the initial lesion (no clear cut dividing line).

  2. Accumulation of lymphoid cells immediately subjacent to junctional epithelium at the site of acute inflammation

  3. Cytopathic alterations in resident fibroblasts possibly associated with interactions with lymphoid cells.

  4. Further loss of collagen fiber network supporting the marginal gingiva. (Collagen loss may reach 60-70% within the reaction site)

  5. Beginning proliferation of the basal cells of the junctional epithelium

Established Lesion (2-3 weeks):

  1. Persistence of the manifestations of acute inflammation

  2. Predominance of plasma cells but without appreciable bone loss

  3. Presence of immunoglobulins extravascularly in the CT and JE

  4. Continuing loss of CT substance noted in the early lesion

  5. Proliferation, apical migration, and lateral extension of the junctional epithelium. Early pocket formation may or may not be present.

Advanced Lesion:

  1. Persistence of features described for the established lesion

  2. Extension of the lesion into alveolar bone and PDL with significant bone loss

  3. Continued loss of collagen subjacent to the pocket epithelium with fibrosis at more distant sites

  4. Altered plasma cells in the absence of altered fibroblasts

  5. Read More

Implants- Biological Principles: Osseointegration and bone interface

HOME Implant Home 

  • Giannobile, et al. Bone as a Tissue (CH 4). Clinical Periodontology and Implant Dentistry, Lindhe, J.; Lang, K. 5th Edition, 2008, Blackwell Munksgaard (Volume 1).

  • Lindhe, Berglundh, Lang. Osseointegration (CH 5). Clinical Periodontology and Implant Dentistry, Lindhe, J.; Lang, K. 5th Edition, 2008, Blackwell Munksgaard (Volume 1).

  1. Boioli L et al: A meta-analytic, quatitative assessment of osseointegration establishment and evolotuin of submerged and non-submerged endosseous titanium oral implants. Clin Oral Implants Res. 12: 579-88, 2001 (Duplicate from Implant I)

  2. Albrektsson T et al: The long term efficacy of currently used dental implants: A review and proposed criteria of success. Int J Oral Max Implants 1:11-26, 1986 (Duplicate from implant I)

  3. Albrektsson, T et al: Biological aspects of implant dentistry: Osseointegration. Periodontology 2000 4:58-73, 1994

  4. Trisi, P., Rebaudi A: Progressive bone adaptaion of titanium implants during and after orthodontic load in humans. Int J Periodontics Restorative Dent. 2002 Feb; 22(1):31-43

  5. Abrahamsson I, Berglundh, T, et al. Early bone formation adjacent to rough and turned endosseous implant surfaces. An experimental study in the dog Clinical Oral Implants Research, 15 (2004), pp. 381–392

  6. Berglundh T, Abrahamsson I, et al. Bone healing at implants with a fluoride-modified surface: an experimental study in dogs. Clinical Oral Implants Research, 18 (2007), pp. 147–152

  7. Mathieu V, Vayron R, et al. Biomechanical determinants of the stability of dental implants: Influence of the bone-implant interface properties. J Biomech. 2014 Jan 3;47(1):3-13. doi: 10.1016/j.jbiomech.2013.09.021. Epub 2013 Oct 10.

  8. Greenstein G, Cavallaro J, Tarnow D. Assessing bone’s adaptive capacity around dental implants: a literature review. J Am Dent Assoc. 2013 Apr;144(4):362-8.

  9. Mangano C, Piattelli A, et al. Evaluation of peri-implant bone response in implants retrieved for fracture after more than 20 years of loading. A case series. J Oral Implantol. 2013 Aug 21. [Epub ahead of print]

  10. Barewal R et al: Resonance Frequence Measurment on Implant Stability in Vivo on Implants with a Sandblasted and Acid – Etched Surface. Int J Oral Maxillofac Implants 2003; 18:641-651

  11. Alsaadi, G et al: A Biomechanical assessment of the relation between the oral implant stability at insertion and subjective bone quality assessment . J Clin Periodontol 2007; 34:359-366


Topic: Platform-Switched laser-microchannel implants          assessment of osseointegration

Authors:Boioli L et al

Title: A meta-analytic, quantitative assessment of osseointegration establishment and evolution of submerged and non-submerged endosseous titanium oral implants

Source: Clin Oral Implants Res. 12: 579-88, 2001
Type: Meta-analysis

Rating: Good

Keywords: dental implants, submerged, non-submerged, life table analysis, survival rates, review

Background: Two implant placement methods are used in oral implantology: submerged (S, two-stage surgical procedure) and non-submerged (NS, one-stage surgery). However, a quantitative assessment of their influence on implant osseointegration, summarising the whole present experience, is not directly possible, owing to the lack of normalisation of the published results

Purpose: to help improve the quantitative assessment of this influence by defining normalisation criteria, which would allow the pooling of the results of the studies meeting them and, hence, the statistical treatment of the overall longitudinal results.

Methods:

  • A survey of the literature was performed on studies report on implants placed either with a submerged (S) or a non-sub- merged (NS) procedure. Only root-analogue, threaded implants, exclusively made of titanium, were considered.

  • Among the studies meeting all criteria, 65 concerned S implants and 18 NS implants. One study concerned both S and NS implants.

  • Survival life tables are established (up to 15 and 10 years respectively for S and NS implants placed in normal situations) for extended samples (13049 S and 5515 NS implants).

  • Early (before loading) failure rates and 95% confidence level ranges of cumulative implant survival rates (CSR) have been evaluated.

Results:

  • Both categories match current survival requirements, but with a quite different behavior over time.

  • NS implants, while osseointegrating better initially, are subject to causes of osseointegration loss, which persist over a longer period of time.

  • Implant design characteristics (including the type of surface) seem to be more relevant than the placement procedure for the implant’s behavior.

Conclusion:

  • S and NS implants give acceptable results in terms of survival, and for both categories (but especially for S implants) the placement stage remains a discernible individual cause of failure

  • S implants have been studied more than NS implants, and present less dispersed results; NS implants are particularly affected by a reduced sample after 5–6 years of observation: the findings for this period still require confirmation;

  • NS implants seem to show a better osseointegration establishment, but, unlike S implants, an osseointegration loss process lasting for a longer period of time; subject to further confirmation, the type of placement procedure seems to be of lesser importance for the behavior of the implants, compared with implant design characteristics, including those related to their surface.

Topic: Implant Success

Authors: Albrektsson T, Zarb, Worthington, Eriksson

Tittle: The long term efficacy of currently used dental implants: A review and proposed criteria of success.

Source: Int J Oral Max Implants

Type: Discussion article

Rating: Fair

Keywords: success, osseointegration

Purpose: This paper is an attempt to evaluate currently used dental implant systems and to propose criteria of success.

Discussion:

Observations:

Osseointegration: is a histological definition, and only partially a clinical and radiographic one. An implant can only be judged as osseointegrated in the context of a continuum of observation, since undermining interfacial changes may be gradual, and not evident at the radiographic resolution level at least in the short term. 




Topic:microscopic evaluation ofosseointegration

Authors:Albrektsson T, Johansson C, Sennerby L

Title:Biological aspects of implant dentistry: Osseointegration.

Source:Periodontology 2000 4:58-73, 1994

Type:Discussion/Review

Rating:Good

Keywords:osseointegration

Purpose: To analyze current knowledge on osseointegration.

Discussion:

Radiographic evaluation:

Due to the surrounding bone tissue, an implant may seem to be in direct bone contact even though there is obvious soft tissue coat in reality. The maximal resolution level of radiography, under ideal conditions, is 0.1 mm, which is 10 times the size of a soft tissue cell.

Light microscopic investigations of bone-to-implant interface:

The use of modern cutting and grinding techniques has clearly demonstrated that direct bone-to-implant contact at the light microscopic resolution level is possible with many different metallic and ceramic materials. In loaded clinical cases there are indications that what is referred to as osseointegration depends on material used as one of several factors being important for implant take.

Ultrastructural investigation of experimental implants:

Ultrastructural analysis of the implant-bone interface is technically very difficult, since ultrathin sections are needed for transmission electron microscopy. Most ultrastructural investigations have been performed in animals using metal-coated polycarbonate implants, which permits sectioning, or metal plugs from which the tissue has been separated before sectioning.

Comments on published ultrastructural investigations:

The in vivo interface scenario seems to be completely different from that observed in vitro. In vitro the only cells in direct contact with the implant surface were red blood cells and macrophages, during the early healing phase, and later, multinuclear giant cells. The inner most interface was the last area to be mineralized, and this process seemed to be acellular. The amorphous layer, and in some instance the electron-dense layer, cold be distinguished before extracellular matrix became mineralized.

The commercially pure titanium bone interface in relation to other interfaces:

The interface descriptions found in the literature point to a variability of the interface morphology both for bone-bonding (hydroxyapatite or bioglass) and non-bone-bonding materials (titanium), which is why this type of classification cold be criticized.

The ultrastructure of the bone-titanium interface:

There is one type of amorphous layer in the bone-to-metal interface, even if the width and the content (mineral, collagen, and proteoglycans) has been debated.

Evaluation of retrieved oral implants removed despite a remaining anchorage:

In general, a nonmineralized amorphous layer 200-400 nm wide was bordering the mineralized bone with an electron-dense lamina limitans-like line (50 nm thick). Areas with nonmineralized tissue containing collagen and sometimes osteocytes or vessels were present along the interface.

Conclusion: The only acceptable mode of defining osseointegration is based on clinical examination finding stable implants: a process in which clinically asymptomatic rigid fixation of alloplastic materials is achieved and maintained in bone during functional loading.

Topic: Anatomy       bone adaptaion

Authors: Trisi, P., Rebaudi A

Title:Progressive bone adaptaion of titanium implants during and after orthodontic load in humans.

Source: Int J Periodontics Restorative Dent. 2002 Feb; 22(1):31-43

Type: Histology

Rating: Good

Keywords: orthodontics, implants

Purpose: To evaluate implant stability and peri-implant bone reaction by histologic and clinical evaluation after therapeutic orthodontic loads.

Methods: 41 adult patients received titanium implants (Exacta) as an orthodontic anchorage device; 12 patients received a retromolar or palatal implant to obtain tooth movement. Seven implants were removed at the end of the orthodontic therapy, after 2, 4, 6, and 12 months of orthodontic load, and processed for histologic examination.

Results: It was possible to distalize maxillary and mandibular molars and a group of teeth (molars and premolars), and to obtain tipping, uprighting, intrusion, extrusion, and transfer of anchorage in other parts of the mouth. The results showed that orthodontic therapy is facilitated and quickened using implants. All implants remained stable in the bone up to 12 months of loading, and all were osseointegrated. Microfractures, microcracks, and microcalli were observed around implants that had been placed in both low- and high-density bone. The remodeling rate was still elevated after 18 months.

Conclusion: Loading implants after 2 months of healing was shown to be safe and is considered the standard for orthodontic implants.

Topic: Osseointegration

Title: Early bone formation adjacent to rough and turned endosseous implant surfaces. An experimental study in the dog

Author: Abrahamsson I, Berglundh, T, et al.

Source: Clinical Oral Implants Research, 15 (2004), pp. 381–392

Type: Histologic study, animal model

Rating: Good

Keywords: SLA, osseointegration, implant surface

Objective: To validate a proposed model (as proposed by Berglundh et al. 2003) and to evaluate the rate and degree of osseointegration at turned (T) and sand blasted and acid etched (SLA) implant surfaces during early phases of healing.

Methods: Twenty Labrador dogs received totally 160 experimental devices (solid screw implant with either a SLA or a T surface configuration) as to evaluate healing between 2h and 12 weeks. Histometric and morphometric analyses were performed.

Results: The sections provided an overview of the various phases of tissue formation, while the decalcified, thin sections enabled a more detailed study of events involved in bone tissue modeling and remodeling for both SLA and T surfaces. The initially empty wound chamber became occupied with a coagulum and a granulation tissue that was replaced by a provisional matrix. The process of bone formation started already during the first week. The newly formed bone present at the lateral border of the cut bony bed appeared to be continuous with the parent bone, but on the SLA surface woven bone was also found at a distance from the parent bone. Parallel-fibered and/or lamellar bone as well as bone marrow replaced this primary bone after 4 weeks. In the SLA chambers, more bone-to-device contact, more initial woven bone and earlier lamellar bone formation was found than in the T chambers.

Conclusions:Osseointegration represents a dynamic process both during its establishment and its maintenance. While healing showed similar characteristics with resorptive and appositional events for both SLA and T surfaces, the rate and degree of osseointegration were superior for the SLA compared with the T chambers.

Topic:  Osseointegration

Authors: Berglundh T, Abrahamsson I, et al.

Title: Bone healing at implants with a fluoride-modified surface: an experimental study in dogs.

Source: Clinical Oral Implants Research, 18 (2007), pp. 147–152

Type:Animal study

Rating:Good

Keywords:dental implants, histology, osseointegration, titanium

Purpose: Study early stages of osseointegration to implants with a fluoride-modified surface.

Methods: Six mongrel dogs, about 1-year old, were used. All mandibular premolars and the first mandibular molars were extracted. Three months later, mucoperiosteal flaps were elevated in one side of the mandible and six sites were identified for implant placement. The control implants (MicroThread) had a TiOblast surface, while the test implants (OsseoSpeed) had a fluoride-modified TiOblast surface. Both types of implants had a similar geometry, a diameter of 3.5 mm and were 8 mm long. Following installation, cover screws were placed and the flaps were adjusted and sutured to cover all implants. Four weeks after the first implant surgery, the installation procedure was repeated in the opposite side of the mandible. Two weeks later, biopsies were obtained and prepared for histological analysis. The void that occurred between the cut bone wall of the recipient site and the macro-threads of the implant immediately following implant installation was used to study early bone formation.

Results:The amount of new bone that formed in the voids within the first 2 weeks of healing was larger at fluoride-modified implants (test) than at TiOblast (control) implants. It was further observed that the amount of bone-to-implant contact that had been established after 2 weeks in the macro-threaded portion of the implant was significantly larger at the test implants than at the controls.

Conclusions:It is suggested that the fluoride-modified implant surface promotes osseointegration in the early phase of healing following implant installation.

Topic: biomechanical determinants of implant stability

Authors: Mathieu V, Vayron R, et al.

Title:Biomechanical determinants of the stability of dental implants: Influence of the bone-implant interface properties.

Source: J Biomech. 2014 Jan 3;47(1):3-13. doi: 10.1016/j.jbiomech.2013.09.021.

Type: review

Rating: good

Keywords: Biomechanical properties; Bone; Implant; Osseointegration; Stability

Background: Dental implants are widely used however, risks of failure are still experienced and remain difficult to anticipate. The stability of biomaterials inserted in bone tissue depends on multiscale phenomena of biomechanical (bone-implant interlocking) and of biological (mechanotransduction) natures.

Purpose: to provide an overview of the biomechanical behavior of the bone-dental implant interface as a function of its environment by considering in silico (via computer simulation), ex vivo and in vivo studies including animal models as well as clinical studies.

Discussion:

Description of the bone-implant interface: the interface has a complex nature due to (i) its roughness, (ii) the fact that bone is in partial contact with the implant, (iii) adhesion phenomena between bone and the implant and (iv) the time-evolving nature of the interface properties.

  • Geometrical description; bone-implant distance and micromotions: When primary stability is not sufficient, micro-movements may appear preventing good healing conditions and leading to the formation of fibrous tissue and to surgical failure. Some studies show that micromotion should not exceed 150 µm, however the precise threshold is not yet known.

  • Mechanical description: stresses and the interface; When functional loading exerted via the implant exceeds “a certain stress”, the implant is regarded as being “overloaded”, leading to possible complications such as peri-implant bone resorption. However, stresses below that are beneficial for the implant outcome and stimulate bone remodeling phenomena. The determination of the value of that threshold remains unclear.

  • Dynamic description: bone remodeling and osseointegration; implant osseointegration was discovered by Branemark. Diagram bellow shows the multi-scale and multi-time nature of the different phenomena occurring during osseointegration; Factors related to implant properties (dashed lines), to the surgeon (dotted line) and the ones relating to bone properties (solid lines).

Implant stability: a space-time multiscale issue

  • Measurement of the multiscale bone properties around the interface:

    • Histology: the gold standard measurement.

    • Small angle X-ray scattering (SXAS): is used to assess thickness, orientation, and shape/arrangement of the mineral crystals in bone tissue. Gives information about bone mineralization but no information about mechanical properties

    • Nanoindentation: investigates biomechanical properties in the microscopic scale. Has shown that Young’s modulus and hardness values are lower in the vicinity of the implant than in mature bone.

    • Scanning Acoustic Microscopy (SAM): qualitative assessment of the biomechanical microstructural properties of bone-implant interface

    • Micro Brillouin scattering: uses the photo acoustic interaction between a laser beam and a sample to measure bone speed of sound

  • Homogenization approaches of bone tissue around the interface: homogenization techniques have been developed to climb the hierarchy of scales in newly formed bone tissue, from the nanoscale up to the macroscopic level.

  • Multiscale biomechanical modeling of the bone-implant interface: Various approaches have been developed to model the mechanical behavior of the bone–implant interface such as; Finite element methods (FEM), Frictional coulomb law, non-linear anisotropic FEM, …

Implant stability assessment

  • X-ray and MRI based techniques: Limited resolution of clinical X-ray based techniques due to metal artifacts related to the presence of the implant metallic components. MRI has also been proposed but is also of limited interest due to magnetic fields disturbance. Maximum resolution level of radiography is 0.1mm which is ten times the size of a soft tissue cell. X-ray or MRI based techniques are not commonly used in order to assess the biomechanical properties of bone to implant interface

  • Invasive biomechanical methods: Tensional test, Push out/Pull out test, Removal torque analysis

  • Non-invasive biomechanical methods:

    • Empirical approaches; Hitting the implant with an instrument and listen to the noise made by the system. Insertion torque during the surgical procedure.

    • Impact based approaches: PerioTest device (Schulte et al. 1980) was originally used for evaluation of tooth mobility. Measurement leads to PerioTest value (PTV), -8 to 50. PTV correlates to mobility and level of marginal bone.

    • Resonance frequency analysis: Measurement of the first resonance frequency of the bone–implant system. Uses an L-shaped transducer or a “Smartpeg”, which is a piece screwed in the implant abutment. Measurement gives an index called Implant Stability Quotient (ISQ 0-100), system is commercialized under the name Osstell. A correlation was shown between initial ISQ value and; (i) cutting torque, (ii) bone measurements assessed empirically by the surgeon during implant placement, (iii) Cortical bone thickness, (iv) Anatomical region of implantation. Limitations:

      • Only captures the first resonance frequency, which is of limited value from a structural mechanics point of view (“oversimplification”)

      • Sensitivity of ISQ value to the implant stability depends on the implant type

      • Relationship between ISQ values and BIC remains unclear

      • Fixation and orientation of the transducer (or smartpeg) influence significantly the ISQ values

      • ISQ values are related to the bone properties at the scale of the organ, but properties at the scale of 50-200μm are critical for osseointegration

    • Quantitative ultrasounds methods: Used to assess bone mineral status, enamel thickness. Several studies show the potentiality of QUS to investigate bone quality around implants, further work is necessary.

Topic:Bone           adaptive capacity

Author:Greenstein G, Cavallaro J, Tarnow D.

Title: Assessing bone’s adaptive capacity around dental implants: a literature review.

Source:J Am Dent Assoc. 2013 Apr;144(4):362-8

Type:Review

Reviewer: Phillip Crum

Rating: Good

Keywords:Bone; dental implants; osseointegration; resorption

Purpose:To review concepts pertaining to bond adaptation that may account for high survival rates of prostheses that are subjected to increased stresses.

Discussion:

Bone Mechanotransduction

  • Mechanotransduction=the mechanism that permits bone to detect stimuli.

  • It is thought that bone cells sense and respond to their mechanical environment by changing their biological and biochemical actions.

  • It is strain, not stress, that precipitates alteration of the bone response

  • 3 Possible stimuli for Osteocytes

    • 1-Direct mechanical stimulation

    • 2-Fluid flow induced by shear stress

    • 3-Bone Microdamage

  • The prevailing concept suggests that under dynamic loading, bone matrix deformation produces an interstitial fluid flow. This flow creates shear stress that stimulates osteocytes. Osteocytes act as mechanosensors and convey signals to adjacent cells (osteoblasts) through the intercellular communication network.

Rules For Bone Adaptation to Mechanical Stimuli

  • According to Turner, the following 3 rules characterize the response of bone to stress

    • Bone adaptation is determined by dynamic, rather than static, loading, and it is the alteration of stress, not its consistency, that produces bone modifications

    • A short episode of mechanical loading is required to begin the adaptive response

    • Bone cells accommodate to customary mechanical loading, making them less responsive to routine loading signals.

  • From these, it can be deduced that abnormal stress and strains drive structural change.

Stresses and Strains on Bone

  • Magnitude of occlusal load, cycle number, direction and frequency all can affect the quantity of stress.

  • The relationship between stress and strain establishes the modulus of elasticity (stiffness) of a material.

  • According to Frost, a certain amount of stress is required to maintain bone homeostasis.

    • Microstrains from 0 to 50atrophy

    • 50 to 1500normal bone modeling

    • 1500 to 3000overload

    • >3000possible destruction

Bone Microdamage

  • Fatigue: bone has lost strength and stiffness due to repetitive loads.

  • Microcracks: a discontinuity in the calcium-rich matrix and reflects fissures and breaks in the hydroxyapatite.

Bone’s Proliferative response to stress around dental implants

  • If the load is above a certain threshold, bone loss or loss of osseointegration can occur.

  • If functional load is below a destructive threshold, it can be stimulatory and induce apposition of bone and increased osseous density.

  • There is much evidence that supports the concept that bone can respond to stress and modify itself to withstand increased mechanical forces.

Remodeling

  • Jee estimated that about 20 percent of the cortical and cancellous bone surfaces (endosteal and periosteal) are remodeling at any point in time.

  • The replacement rate of cortical bone is 7.7% per year

  • The replacement rate of cancellous bone is 17.7% per year

  • Garetto showed that within 1mm of implants, there was a layer of bone that remodeled rapidly. The turnover rate was three to nine times faster per year within the 1mm of the implants.

  • Bones such as the mandible that experience loading from varying directions exhibit more platelike trabecular architecture. An advantage of this structure is its ability to manage forces from different directions.

  • High load areas usually manifest dense platelike architecture, whereas low load areas usually demonstrate low-density rodlike structures.

Conclusion: There are 2 possible explanations for the success of prosthetic constructs. First, is that bone is stronger than expected and can tolerate increased stress. Second is that as long as the stress/strain level does not increased beyond a threshold that causes bone destruction, bone has the ability to remodel and model and increase its osseous density.

Topic: Fracture

Authors: Mangano C, Piattelli A, Mortellaro C, Mangano F, Perroti V, Iezzi G

Title: Evaluation of peri-implant bone response in implants retrieved for fracture after more than 20 years of loading. A case series

Source:J Oral Implantol. 2013 Aug 21

Type: Case series

Rating: Good

Keywords: Bone remodeling, human histology, implant surfaces, retrieved dental implants

Purpose: To present a histological case series of the peri-implant bone responses in implants retrieved for fracture after more than 20 years loading period.

Methods: 5 implants retrieved for bodily fracture in 5 patients were found to be analyzed. The surface of these implants was obtained by sandblasting, followed by acid-etching for 30 minutes. The implants were then washed with hydrogen peroxide and dried with high heat. None of the implants were immediately loaded. In 3 cases, implants supported partial fixed bridges, while in 2 cases there was a mandibular ovendenture supported by 2 implants. Four implants were located in the mandible, and 1 in the maxilla. All implants were retrieved with a 5-mm trephine bur. Histological analysis and histomorphometry of the percentages of bone-implant contact were carried out.

Results: Compact, mature bone in close contact with the implant surface was observed in all specimens, with no gaps or connective tissue at the interface. Primarily newly formed bone was observed in proximity of the implant surface. In the most coronal portion of one implant, connective tissue adhering to the implant surface was detected. Bone-to-implant contact percentage ranged from 37.2-76%.

Conclusion: Implant effectiveness is largely dependent on biological stability and integration between bone and implant. Endosseous implants may function over a wide range of degrees of osseointegration.

Topic:sandblasted and acid-etched implant surfaces
Authors:Barewal R et al.
Title: Resonance frequency measurement of implant stability in vivo on implants with a sandblasted and acid-etched surface.

Source: J Oral Maxillofac Implants 2003; 18:641-651

Type: Clinical Study

Rating: Good

Keywords: bone, clinical trials, dental implants, early healing, endosseous dental implantation,

implant stability, resonance frequency analysis

Purpose: to understand pattern of stability changes and early healing around single-stage roughened-surface implants during the first 2 ½ months in different bone types.

Methods: Twenty patients had 1 to 4 implants placed in the posterior maxilla or mandible. Bone type was classified into 1 of 4 groups according to the Lekholm and Zarb index (1985). RFA was used for direct measurement of implant stability on the day of implant placement and consecutively once per week for 6 weeks and at weeks 8 and 10.

Results:

Conclusion: The lowest values for interfacial stiffness between the bone and the implant were found at 3 weeks, particularly in type 4 bone. Healing responses of Types 2 and 3 bone were more similar to Type 1 than to Type 4 bone. The RF values at 6 weeks did not differ from those at 10 weeks in all bone types; this supports the idea of a 6-week healing period for ITI implants in Types 1, 2, and 3 bone. The lack of significant change in stability from 5 to 10 weeks for Types 1, 2, and 3 bone supports further testing of an even shorter healing protocol. With regards to Type 4 bone, the current 12- week healing period could be evaluated and potentially shortened.

Topic: implant stability per bone type

Authors: Alsaadi G, Quirynen M, Michiels K, Jacobs R, Steenberghe D

Title:A biomechanical assessment of the relation between the oral implant stability at insertion and subjective bone quality.

Source: Journal of Clinical Periodontology 2007; 34: 359-366.

Type: Clinical

Reviewer: Cynthia Goldin

Rating: Good

Keywords:biomechanics; bone quality; dental implants; insertion torque; oral implants; osseointegration; periotest; RFA

Purpose:To evaluate the validity of subjective bone quality assessment.

Methods:A total of 298 patients treated with implants. Bone quality assessment performed immediately after implant placement and using the Lekholm & Zarb index. Tactile sensation was assessed for cortical bone and trabecular bone during high speed drilling. A scale from 1 (very thick cortex/dense trabecular bone) – 3 / 4 (thin/ poorly mineralized trabecular bone). The bone quality was assessed during implant insertion by an electronic torque force measurement device, which measures the torque force while tapping or inserting the implant at slow speed. The rigidity of implant-bone continuum was assessed by resonance frequency analysis taken at implant insertion and before abutment insertion, through a peg attached to the fixture, and an ISQ value is presented. This runs from 1-100, the higher the ISQ the more stable the implant. Periotest also measured the rigidity. After connecting a temporary abutment 4 mm in length, this device measures the damping capacity of the implant bone continuum. A rod is placed perpendicular to the abutment at a distance of 2 mm and it is accelerated electromagnetically. When rod hits the implant, it is decelerated. The faster the deceleration, the greater implant stability. Values range from -8 (very stable) to +50 (extremely mobile).

Results:Subjective assessment was related to PTV, ISQ and placement torque in the crestal, the second and the apical third.

ISQ and PTV were also compared with the bone quality assessed according to the Lekholm & Zarb index. A significant relationship was detected.

– Grade 1: 5.3, 73.3

– Grade 3 or 4: 1.6, 55

ISQ and PTV recorded at implant insertion were also compared with the bone quality assessed according to the surgeon’s tactile sensation. A significant relationship was detected between ISQ, PTV and cortical bone grades and between ISQ and trabecular bone grades

For surgeon’s tactile sensation, a good correlation was noted for the presence of a thick cortex: – 4.6, 70.3 or a thin one: – 0.3, 65.9. For dense trabecular bone, the values were – 2.8, 69.4 while for poor trabecular bone, the values were – 1.7, 66.4

Conclusion:

Subjective assessment of bone quality is related to PTV, ISQ and placement torque measurements at implant insertion.

DesignedBy StevenJ. Spindler, DDS LLC

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Implants – Review of dental implants. Synopsis

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Longitudinal studies: survival and success of implants

  • Lang and Salvi. Implants in Restorative Dentistry (CH 52). Clinical Periodontology and Implant Dentistry, Lindhe, J.; Lang, K. 5th Edition, 2008, Blackwell Munksgaard (Volume 2).

  • Misch. Rational for Dental Implants. (CH 1). pp 3-25. Contemporary Implant Dentistry, Misch, C.E., 3rd Edition, 2008, Mosby Year Book.

  • Cochran, D: Implants Therapy I. Proceeding of the 1996 World Workshop in Periodontics 1:707-795, 1996

  • Fritz, M: Implants Therapy II. Proceedings of the 1996 World Workshop in Periodontics 1: 796-815,1996

  1. Boioli L et al: A meta-analytic, quatitative assessment of osseointegration establishment and evolution of submerged and non-submerged endosseous titanium oral implants. Clin Oral Implants Res. 12: 579-88, 2001

  2. Albrektsson T et al: The long term efficacy of currently used dental implants: A review and proposed criteria of success. Int J Oral Max Implants 1:11-26, 1986

  3. Misch CE, Perel ML, Wang HL, et al. Implant success, survival, and failure: the International Congress of Oral Implantologists (ICOI) Pisa Consensus Conference. Implant Dent. 2008 Mar;17(1):5-15.

  4. Klokkevold P et al: Current status of dental implants: A periodontal perspective. Int J Oral Maxillofac Implants 15: 56-65, 2000

  5. Salinas TJ, Eckert SE. In patients requiring single-tooth replacement, what are the outcomes of implant- as compared to tooth-supported restorations? Int J Oral Maxillofac Implants. 2008 Jan-Feb;23(1):56.

  6. Simonis P, Dufour T, Tenenbaum H. Long-term implant survival and success: a 10-16-year follow-up of non-submerged dental implants. Clin Oral Implants Res. 2010 Jul;21(7):772-7.

  7. Ueda T, Kremer U, Katsoulis J, Mericske-Stern R. Long-term results of mandibular implants supporting an overdenture: implant survival, failures, and crestal bone level changes. Int J Oral Maxillofac Implants. 2011 Mar-Apr;26(2):365-72.


Topic: Platform-Switched laser-microchannel implants      submerged and non-submerged implants

Authors: Boioli L et al

Title: A meta-analytic, quatitative assessment of osseointegration establishment and evolution of submerged and non-submerged endosseous titanium oral implants

Source: Clin Oral Implants Res. 12: 579-88, 2001
Type: Meta-analysis

Rating: Good

Keywords:dental implants, submerged, non-submerged, life table analysis, survival rates, review

Background: Two implant placement methods are used in oral implantology: submerged (S, two-stage surgical procedure) and non-submerged (NS, one-stage surgery). However, a quantitative assessment of their influence on implant osseointegration, summarising the whole present experience, is not directly possible, owing to the lack of normalisation of the published results

Purpose: to help improve the quantitative assessment of this influence by defining normalisation criteria, which would allow the pooling of the results of the studies meeting them and, hence, the statistical treatment of the overall longitudinal results.

Materal and methods:

  • A survey of the literature was performed on studies report on implants placed either with a submerged (S) or a non-sub- merged (NS) procedure. Only root-analogue, threaded implants, exclusively made of titanium, were considered.

  • Among the studies meeting all criteria, 65 concerned S implants and 18 NS implants. One study concerned both S and NS implants.

  • Survival life tables are established (up to 15 and 10 years respectively for S and NS implants placed in normal situations) for extended samples (13049 S and 5515 NS implants).

  • Early (before loading) failure rates and 95% confidence level ranges of cumulative implant survival rates (CSR) have been evaluated.

Results:

  • Both categories match current survival requirements, but with a quite different behavior over time.

  • NS implants, while osseointegrating better initially, are subject to causes of osseointegration loss, which persist over a longer period of time.

  • Implant design characteristics (including the type of surface) seem to be more relevant than the placement procedure for the implant’s behavior.

Conclusion:

  • S and NS implants give acceptable results in terms of survival, and for both categories (but especially for S implants) the placement stage remains a discernible individual cause of failure

  • S implants have been studied more than NS implants, and present less dispersed results; NS implants are particularly affected by a reduced sample after 5–6 years of observation: the findings for this period still require confirmation;

  • NS implants seem to show a better osseointegration establishment, but, unlike S implants, an osseointegration loss process lasting for a longer period of time; subject to further confirmation, the type of placement procedure seems to be of lesser importance for the behavior of the implants, compared with implant design characteristics, including those related to their surface.

Topic:Implant Success

Authors:Albrektsson T, Zarb, Worthington, Eriksson

Tittle: The long term efficacy of currently used dental implants: A review and proposed criteria of success.

Source: Int J Oral Max Implants

Type: Discussion article

Rating: Fair

Keywords: success, osseointegration

Purpose: This paper is an attempt to evaluate currently used dental implant systems and to propose criteria of success.

Discussion:

Observations:  Osseointegration: is a histological definition, and only partially a clinical and radiographic one. An implant can only be judged as osseointegrated in the context of a continuum of observation, since undermining interfacial changes may be gradual, and not evident at the radiographic resolution level at least in the short term. 


Topic:Implant success, survival, and failure

Authors:Misch CE, Perel ML, Wang HL

Title:Implant success, survival, and failure: the International Congress of Oral Implantologists (ICOI) Pisa Consensus Conference.

Source:Implant Dent. 2008 Mar;17(1):5-15.

Type:Consensus discussion

Rating:Good

Keywords:implant clinical success, implant clinical survival, implant clinical failure

Purpose: To propose 4 clinical categories that contain conditions of implant success, survival, and failure.

Discussion:

Survival conditions:

Satisfactory survival: an implant with less than ideal conditions, yet does not require clinical management

Compromised survival: implants with less than ideal conditions, which require clinical treatment to reduce the risk of implant failure

Implant failure: implants that require removal or have already been lost

Implant success: should include a time period of at least 12 months loading. Early implant success is 1-3 years, intermediate 3-7 years, long term success more than 7 years

Clinical indices:

Pain: Once implant has achieved primary healing, absence of pain under vertical or horizontal forces is a primary subjective criterion. Pain should not be associated with the implant after healing. Usually, pain form the implant body does not occur unless the implant is mobile and surrounded by inflamed tissue or has rigid fixation but impinges on the a nerve. Pain during function can place the implant in the failure category. Sensitivity during function may place the implant in the survival category and may warrant clinical treatment.

Mobility: Lack of clinical movement does not mean the true absence of mobility. Lack of mobility usually means that at least a portion of the implant is in direct contact with bone, although the percentage of bone contact cannot be specified. A clinically mobile implant indicates the presence of connective tissue between the implant and bone (failure).

Radiographic crestal bone loss: The marginal bone around implant crestal region is usually a significant indicator or implant health. The Pisa Consensus suggests that the clinical assessment for each implant monitors marginal bone loss in increments of 1.0 mm. The bone loss measurement should be related to the original marginal bone level at implant insertion, rather than to a previous measurement.

Probing depths: Probing depths may be of little diagnostic value unless accompanied by signs and/or symptoms. It is of benefit to probe and establish a baseline measurement after the initial soft tissue healing around the permucosal aspect of the implant. Increases in this baseline measurement over time most often represents marginal bone loss.

Peri-implant disease: Exudate or an abscess around an implant indicates exacerbation of the peri-implant disease and possible accelerated bone loss. An exudate persisting more than 1-2 weeks usually warrants surgical revision of the peri-implant area to eliminate causative elements.

The ICOI Pisa Implant Quality of Health Scale

Conclusion:

Implant success is as difficult to describe as the success criteria for a tooth. Implant failure is easier to describe than implant success or survival and may consist of a variety of factors. Any pain, vertical mobility, and uncontrolled progressive bone loss warrant implant removal.

Topic: Periodontal considerations around dental implants

Authors: Klokkevold P et al

Title: Current status of dental implants: A periodontal perspective

Source: Int J Oral Maxillofac Implants 15: 56-65, 2000

Type: Review

Rating: Good

Keywords: dental implants

Purpose: To provide an overview of the current status of implants as related to the practice of periodontics.

Discussion:

RESTORING FORM, FUNCTION AND ESTHETICS:

The prosthetic position was not thought to be critical to the success of implants, and therefore it was not a major consideration. However due to the esthetic demands of patients, implant therapy has become increasingly focused on prosthetically driven implant position. Several new evidence-based guidelines emerged from prosthetically driven implant positioning, including the need to reconstruct hard and soft tissues that had been lost, so a bone augmentation or bone regenerative procedure had to be considered.

PERI-IMPLANT PATHOLOGY AND IMPLANT FAILURE

Peri-implant pathology, or more specifically periimplant bone loss, has been attributed to several different factors, including poor surgical management, failure to achieve osseointegration, premature loading, biomechanical overload, peri-implant infection, and impaired host response.

PERI-IMPLANT TISSUE ANATOMY FROM THE PERIODONTAL PERSPECTIVE

Osseointegrated dental implants do not have any connective tissue fiber attachments. Osseointegrated dental implants by definition do not have any soft tissues intervening between the implant surface and the bone. There are no collagen fibers attached to the implant surface. There is a connective tissue network of fibers around the implant coronal to the level of supporting bone. The supra-bony connective tissue surrounding the implant is made up of circumferential fibers that run parallel to the implant surface.

BIOLOGIC DIMENSION OF SOFT TISSUES AROUND IMPLANTS

Regardless of the type of implant used and the soft tissue dimensions at the time of placement, the authors found that a 2-mm-long junctional epithelium and a 1-mm zone of connective tissue were consistently established.

PERI-IMPLANTITIS

Peri-implantitis is defined as an inflammatory process affecting the tissues around an osseointegrated implant in function that results in loss of supporting bone, while peri-implant mucositis is an inflammatory process distinguished from periimplantitis by the lack of bone loss.

TREATMENT OF PERI-IMPLANTITIS

The most important aspect of treatment for peri-implantitis is to stop the progression of bone loss by controlling bacterial infection. As with periodontal therapy, the goal of surgical therapy is complete debridement of the defect, decontamination of the implant surface, and possibly removal of any porous implant surface coatings. Once the inflammatory disease process is controlled, it is possible to attempt regenerative procedures. In addition to bacterial infection, biomechanical overload has been shown to contribute to periimplant bone loss. Bone loss associated with biomechanical overload is most frequently found to be localized around the coronal aspect of the bone-implant interface.

Radiographs should be taken periodically to evaluate potential loss of bone. It has been well established that the amount of bone loss around Brånemark-type implants is approximately 1 to 1.5 mm in the first year after loading and 0.1 mm annually thereafter.

At regular intervals (every 3 to 6 months), implant abutment/restoration surfaces should be debrided of plaque and calculus accumulations.

Conclusion:The combination of in-depth biologic knowledge together with extensive surgical training has given the periodontist the skills to provide the highest quality care to patients around the world.

Topic:Implants vs Fixed Partial Dentures

Title: In patients requiring single-tooth replacement, what are the outcomes of implant- as compared to tooth-supported restorations?

Author: Salinas TJ, Eckert SE.

Source: Int J Oral Maxillofac Implants. 2008 Jan-Feb;23(1):56.

Type: Systematic review

Rating: Good

Keywords: comparative study, prosthodontics, implants compared to FPD, FPD, restorative planning

Purpose:The study provides a systematic review of the literature to determine the long-term survival characteristics of single implant-supported crowns and fixed partial dentures.

Materials and Methods:

A search of the MEDLINE, EMBASE, and Cochrane Collaboration databases was conducted to identify articles that compared survival and success of fixed partial dentures and single implant-supported crowns. In addition to comparative cohort studies, articles that pertained specifically to single implant-supported crowns or fixed partial dentures were included in this review. Inclusion criteria for implant and fixed partial denture articles included a minimum 2-year study, primary publication in the English language, a minimum of 12 implants, implants designed to osseointegrate, and inclusion of data regarding implant and prosthetic performance. Data were analyzed using cumulative proportions of survival and success for both prosthetic types and for individual implants. Wilson score method was used to establish 95% confidence intervals for each population. The chi-square test for homogeneity was performed.

Results: The literature search failed to identify any articles that directly compared survival or success of single implant-supported restorations with fixed partial dentures. Following the search criteria, and independent analysis by reviewers, 51 articles were identified in the implant literature (agreement, 95.42%; kappa coefficient, 0.8976), and 41 were identified in the fixed partial denture literature (agreement, 90.97%; kappa coefficient, 0.7524). Pooled success of single-implant restorations at 60 months was 95.1% (CI: 92.2%-98.0%), while fixed partial dentures of all designs exhibited an 84.0% success rate (CI: 79.1%-88.9%).

Conclusions: Tthis systematic review of the scientific literature failed to demonstrate any direct comparative studies assessing clinical performance of single implant-supported crowns and tooth-supported fixed partial dentures. The analysis suggested differences at 60 months between survival of implant-supported single crowns and natural tooth-supported fixed prostheses when resin-bonded and conventionally retained fixed prostheses were grouped. This difference disappeared when implant-supported single crowns were compared with conventionally retained fixed partial dentures at 60 months. For other time periods, direct comparative data were unavailable.

Topic: Implant survival and success rate

Authors: Simonis P, Dufour T, Tenenbaum H.

Title: Long-term implant survival and success: a 10-16-year follow-up of non-submerged dental implants.

Source: Clin Oral Implants Res. 2010 Jul;21(7):772-7.

Type: Retrospective study

Rating: Fair

Keywords: implant survival, implant success, cumulative survival rate

Purpose: To evaluate the long-term results of dental implants using implant survival and implant success as outcome variables.

Methods: Of the 76 patients who received 162 implants of the Straumann Dental Implant System during the years 1990-1997, 55 patients with 131 implants were recalled 10-16 years after implant placement for a complete clinical and radiographic examination, followed by a questionnaire that examined the degree of satisfaction. The incidence of biological and technical complications has been carefully analyzed for each implant. Success was defined as being free of all these complications over the entire observation period. Associated factors related to peri-implant lesions were analyzed for each implant.

Results: The long-term implant cumulative survival rate up to 16 years was 82.94%. The prevalence of biological complications was 16.94% and the prevalence of technical complications was 31.09%. The cumulative complication rate after an observation period of 10-16 years was 48.03%, which meant that substantial amounts of chair time were necessary following implant placement. The majority of implant losses and biological complications were concentrated in a relatively small number of patients.

Conclusion: Despite a relatively high long-term survival rate, biological and technical complications were frequent. Patients with a history of periodontitis may have lower implant survival rates than patients without a history of periodontitis and were more prone to biological complications such as peri-implant mucositis and peri-implantitis.

Topic: implant-supported overdentures

Authors: Ueda T, Kremer U, Katsoulis J, Mericske-Stern R

Title:Long-term results of mandibular implants supporting an overdenture: implant survival, failures, and crestal bone level changes

Source: Int J Oral Maxillofac Implants. 2011 Mar-Apr;26(2):365-72.

Type: clinical

Rating: good

Keywords: crestal bone loss, dental implants, implant surgical, long-term follow-up study, manifestation of failures,

Purpose:To summarize the long-term clinical observations of edentulous patients treated with mandibular implant-supported overdentures.

Methods: 147 edentulous patients, fairly healthy, admitted to treatment with mandibular implant overdentures in university of Bern, Switzerland. The treatment plan was to connect the dentures to only two implants by means of single ball anchors or bars; in patients with severely reduced ridge (≤ 8mm) or narrow and curved anterior mandible, three implants would be placed. Strauman implants in all pts. One-part implants with 7,9,11,13 or 15 mm, and two-part implants 6,8,10,12, or 14 mm, all 3.3 or 4.1 mm diameter. Non-submerged, single-stage placement, unloaded healing time 3 months then prosths fabricated. Regular maintenance care was provided at least one time per year. The cumulative implant survival rate was calculated. Implant failures were described according to clinical signs at the time of removal and related to the patient’s specific history. Crestal bone measurements were performed using computer software based on panoramic radiographs.

Results:147 patients with 314 implants were evaluated for 10 to 24 years. Of these, 101 patients were still available. Success rate could not be calculated due to absence of regular radiographs to confirm a minimum annual bone loss. Thirteen implants failed during the observation period, resulting in a cumulative survival rate of 85.9% after 24 years. The reasons for removal of implants were peri-implantitis (two implants) and mobility (11 implants). Mean crestal bone loss was 0.54 ± 0.7 mm per implant site after an average observation time of 16.5 ± 3.9 years. The duration of loading had a statistically significant effect on bone loss. NSSD among different subgroups of implants.

Conclusion:The data exhibit a satisfactory survival rate of implants. An individual analysis of implants with late failures did not reveal a typical failure pattern, but loss of implants without signs of infection was more frequent than loss of implants with signs of peri-implantitis.

DesignedBy StevenJ. Spindler, DDS LLC

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45. Diagnosis /Indices – Radiographic Interpretation

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Are Radiographs an accurate method of diagnosing periodontal disease?

  1. HardekopfJ, et al. The “furcation arrow” – A reliable radiographic image? J Periodontol. 58:258 – 261, 1986.

  2. DeasDE, Moritz A., Mealey B et al: Clinical reliability of the furcation arrow as a diagnositc marker. J Periodontol 2006;77;1436-1441

  3. OrtmanL, McHenry K, Hausmann E: Relationship between alveolar bone measured by 1251 absorptiometry with abalsysis of standardized radiographs: 2. Bjorn technique: J Periodntol 1982;53:311-314

  4. BuchananSA, et al: Radiographic detection of dental calculus. J Periodontol. 58:747-751, 1987.

What alveolar crest level represents bone loss on a bitewing radiograph??

  1. HausmanE., Allen K., Clerehugh V. What alveolar crest level on a bite wing radiograph represents bone loss? J Periodontol 1991;62;570-572

Are digital radiographs equivalent to conventional radiographs in revealing bone loss?

  1. KhochtA, Janal M, Harasty L, Chang K: Comparison of direct digital and conventioanl intraoral radiographs in detecting alveolar bone loss. J Am Dent Assoc 2003;134;1468-1475

  2. BruderG, Casale J, Goren, A, Friedman S; Alteration of computer dental radiography images J Endod 1999;25;275-276

Are panoramic radiographs ever of value in periodontics?

  1. KasajA, Vasiliu Ch, Willershausen B. Assessment of alveolar bone loss and angular bony defects on panoramic radiographs. Eur J Med Res. 2008 Jan 23;13(1):26-30.

  2. PerssonRE, Tzannetou S, Feloutzis AG, Brägger U, Persson GR, Lang NP. Comparison between panoramic and intra-oral radiographs for the assessment of alveolar bone levels in a periodontal maintenance population. J Clin Periodontol. 2003 Sep;30(9):833-9.

When should cone beam computed tomography (CBCT) be used?

  1. The American Dental Association Council on Scientific Affairs. The use of cone beam computed tomography in dentistry: An advisory statement from the American Dental Association Council on Scientific Affairs. J Am Dent Assoc 2012;143;899-902

  2. MischKA, Yi ES, Sarment DP: Accuracy of cone beam computed tomography for periodontal defect measurements.. J Periodontol. 2006 Jul;77(7):1261-6.

  3. VandenbergheB, Jacobs R, Yang J. Detection of periodontal bone loss using digital intraoral and cone beam computed tomography images: an in vitro assessment of bony and/or infrabony defects. Dentomaxillofac Radiol. 2008 Jul;37(5):252-60.

What if the significance of the lamina dura?

  1. TibbettsJ, Allen K, Hausmann E: Effect of x-ray angulation on radiographic periodontal ligament space width. J Periodontol 63: 114-117, 1992

  2. GreensteinG, Polson A, et al: Associations between crestal lamina dura and periodontal status. J. Periodontol. 52:362-366, 1981.

Can radiographs be used to detect progression of periodontitis?

  1. SelikowitzH-S, et al: Retrospective longitudinal study of the rate of alveolar bone loss in humans using bite-wing radiographs. J. Clin. Periodontol. 8:431-438,1981.

Are radiographs an accurate way to assess healing after periodontal surgery?   Do newer radiographic techniques improve the usefulness of radiographs?

  1. TobackGA, Brunsvold MA, et al. The accuracy of radiographic methods in assessing the outcome of periodontal regenerative therapy. J Periodont 70:1479-1489,1999.

  2. ZybutzM, Rapoport D, Laurell L, Persson GR. Comparisons of clinical and radiographicmeasurements of inter-proximal vertical defects before and 1 year after surgical treatments. J Clin Periodontol 27:179-186, 2000.

  3. GrimardBA, Hoidal MJ, Mills MP, Mellonig JT, Nummikoski PV, Mealey BL. Comparison of clinical, periapical radiograph, and cone-beam volume tomography measurement techniques for assessing bone level changes following regenerative periodontal therapy. J Periodontol. 2009 Jan;80(1):48-55.

  4. GorenAD, Dunn SM, Wolff M, van der Stelt PF, Colosi DC, Golub LM. Pilot study: digital subtraction radiography as a tool to assess alveolar bone changes in periodontitis patients under treatment with subantimicrobial doses of doxycycline. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2008; Oct;106(4):e40-5. Epub 2008 Aug 20.

How do Radiographic Measurements Compare to Clinical Examination Measurements?

  1. PapapanouPN, Wennstrom JL: Radiographic and clinical assessments of destructive periodontal disease. J Clin Periodontol.16:609-612, 1989.

  2. MachteiEE, Hausmann E, Grossi SG, Dunford R, Genco RJ. The relationship and clinical changes in the periodontium. J Perio Res 32:661-666, 1997.

  3. EickholzP, Hausmann E. Accuracy of radiographic assessment of interproximal bone loss in intrabony defects using linear measurements. Euro J Oral Sci 108:70-73, 2000.

  4. PilgramTK, Hildebolt CF, et al. Relationships between radiographic alveolar bone height and probing attachment level: data from healthy post-menopausal women. J Clin Perio 27:341-346, 2000.

Comparison of Techniques

  1. ReedBE, Polson AM : Relationships between bitewing and periapical radiographs in assessing crestal alveolar bone levels. J. Periodontol. 55:22-27, 1984.

Reviews

  1. BennDK. A review of the reliability of radiographic measurements in estimating alveolar bone changes. J. Clin. Periodontol. 17:14-21, 1990. (Review)

  2. JeffcoatMK. Radiographic methods for the detection of progressive alveolar bone loss. J Periodontol 63: (Suppl 4) 367-372, 1992. (Review)

  3. TugnaitA, Clerehugh V, Hirschmann PN. The usefulness of radiographs in diagnosis and management of periodontal diseases: a review. J Dent 28:219-226, 2000. (Review)

  4. KimIH, Mupparapu M.Dental radiographic guidelines: a review.Quintessence Int. 2009 May;40(5):389-98. Review


Are Radiographs an accurate method of diagnosing periodontal disease?

Topic:Furcation Arrow

Authors:Hardekopf J, et al.                               ARTICLE

Title:The “furcation arrow” – A reliable radiographic image?

Source:J.Periodontol.58:258-261,1986.
Type: Clinical study

Rating: Good

Keywords:Furcation Arrow, Radiograph

Furcation Arrow:Small triangular shadow across the mesial or distal roots of maxillary molars. Indicates class II or class III involvement.

P: To determine whether there is a consistent relationship between furcation arrows on radiographs and proximal bony furcation involvement in maxillary molars.

M&M: 45 adult human skulls with proximal furcation involvement in maxillary 1st or 2nd molars were used. 66 Degree 1, 53 Degree 2, 43 Degree 3 proximal furcation involvements. An additional 120 proximal furcations without bony involvement served as controls. Furcation classifications were determined independently by two examiners. Each maxillary molar was radiographed radiographed. Film placement was standardized to minimize interproximal overlap and to position the film lingually/palatally on a plane that paralleled the buccal surfaces of the teeth radiographed. Evaluations for the presence of the furcation arrow were made independently by 6 dentists as the radiographs were projected onto a screen. Projected radiographs with identifiable “arrow” images were used.

R: Incidence of furcation arrow image over degree 2 and 3 involvements was significantly greater than that observed over the uninvolved controls. The incidence of the furcation arrow image over the 120 uninvolved proximal furcations was low (18% for mesial and 7% for distal furcations). There was NSD between degree 1 involvement and the controls in the incidence of the furcation arrow image. There was an equal number of furcation arrows observed over mesial and distal furcations. The existence of a buccal furcation involvement of any degree did not influence the appearance of the furcation arrow. The image was no more likely to be observed over Degree 3 involvement than over Degree 2 involvement.

D: As the extent of furcation involvement increased, so did furcation arrow image.  Degree 3 involvement reflected the radiographic image > 50% of the time. The furcation arrow seldom appears over uninvolved furcations, its appearance indicates that there is proximal bony furcation involvement. Absence of arrow does not indicate the absence of a bony furcation involvement.  Root morphology and horizontal angulation of the tube head may be factors in determining whether a given furcation defect will exhibit an arrow.    

BL: The radiographic presence of the furcation arrow appears to be a reliable diagnostic tool for the clinician when evaluating bony furcation involvement.

Topic:Furcations

Authors: Deas DE, Moritz A., Mealey B                               NO ARTICLE

Title:Clinical reliability of the furcation arrow as a diagnositc marker.

Source: J Periodontol 2006;77;1436-1441

Type:Clinical study

Rating: Good

Keywords:Furcation involvement, periapical, bitewings

B:Traditionally, radiographic assessment in conjunction with clinical probing using a curved explorer or furcation probe has been the chief diagnostic methods used for detecting and characterizing furcation involvement.

P:To evaluate the furcation arrow in a clinical setting, with emphasis on testing the assertion that the radiographic presence of a furcation arrow reliably identifies a furcation invasion.

Questions answered: 1. What is the prevalence of furcation arrow images in the radiographs of maxillary molars with periodontitis? 2. What is the interexaminer agreement on what constitutes a furcation arrow? 3. How does the presence or absence of a furcation arrow correlate with the true clinical status of the furcation? 4. What is the sensitivity and specificity of the furcation arrow as a diagnostic indicator?

M&M:89 patients were referred between February 2004-June 2005 for treatment of moderate to advanced periodontitis that required surgical access to at least one maxillary posterior sextant. Before surgery, one of five calibrated examiners viewed PA and BW radiographs of the surgical site and recorded the presence or absence of a furcation arrow at each proximal furcation. Before administering anesthesia, the same examiner recorded a Hamp index value of each proximal furcation. After flap reflection and debridement, the examiner recorded a second Hamp index at each proximal furcation. After surgery, each of the four remaining examiners independently reviewed the radiographs for furcation arrows. Descriptive statistical analysis was performed to correlate the appearance of the furcation arrow image to the actual degree of furcation invasion as determined by the intrasurgical Hamp index.

R:

  • 164 maxillary molars were examined, providing 328 interproximal furcations

  • 111/328 (33.8%) furcations were determined at surgical debridement to have a furcation invasion of Hamp degree of 1 or greater.

  • When comparing the appearance of the radiographic image to the extent of furcation invasion, 20/64 (31.3%) Hamp 1 furcation invasions and23/47 (48.9%) Hamp 2 and 3 furcation invasions were predicted by furcation arrows observed by at least three of five examiners.

  • The multirater k statistic for interexaminer agreement on the presence or absence of the image was 0.489 (low)

  • The sensitivity of the furcation arrow image as a diagnostic marker was 38.7%, and the specificity was 92.2%  Most actual furcation invasions were not associated with a furcation arrow: a high number of false negatives. The absence of a furcation arrow had a much higher likelihood of not having an accompanying furcation invasion present: a low number of false positives.

  • The positive predictive value of the image was 71.7%, and the negative predictive value was 74.6%.

  • Of the 324 furcations used to compare clinical indices, the agreement of pre-anesthesia and post-debridement Hamp indices was 0% for degree 3, 83.7% for degree 2, and 98.4% for degree 1 furcation lesions.

C:Clinical probing, post-anesthetic sounding and surgical access provide more diagnostic data about furcations than the radiographs to the clinicians. The image is difficult to interpret and highly subjective and can correctly predict furcation invasions only 70% of the time when present on the radiograph. In addition, when furcation invasions are truly present, the furcation arrow is seen in <40% of sites.

Topic:standardized radiographs

Authors: Ortman L, McHenry K, Hausmann E                              NO ARTICLE

Title:Relationship between alveolar bone measured by 1251 absorptiometry with analysis of standardized radiographs: 2. Bjorn technique

Source:J Periodntol 1982;53:311-314

Type:Skull study

Rating:Fair

Keywords:standardized radiographs, Bjorn technique

B:Bjorn developed a bone scoring technique using the projected 5x magnification of periapical radiographs on a scale which divides the tooth into 5% portions.

P:To compare the Bjorn and Henrikson (125I absorptiometry) techniques in their ability to detect small bone changes.

Omnell demonstrated that established principles of radiation absorptiometry permitted measurement of alveolar bone mineral mass. Henrikson applied these principles to development of an 125I absorptiometry technique capable of detecting alveolar bone mass changes on the order of 5%. The technique utilizes an essentially monoenergetic radiation beam, a collimating device and a scintillation counter for directly determining the amount of absorbed radiation.

M&M: 4 periodontal defects were created in dried human skulls between 1stand 2nd PM and 1st M of differing sizes, with incremental reduction of approximately 10%. The defects were made either by reducing the buccal wall or creating crater like defects and were measured using both of the techniques utilizing stents for standardization.

R:In initial bone loss, the Bjorn technique consistently underestimated the amount. 53% of the bone as measured by 125I absorptiometry needed to be reduced before the Bjorn technique could detect any loss. In advanced bone loss, the Bjorn technique was shown to overestimate the amount of loss in 2 of the sites and underestimate in the two other sites.

Conclusion:When bone loss is under 30%, the Bjorn technique tends to underestimate how much true loss has occurred and when over 60%, it is inconsistent.

Topic:Radiography

Authors: Buchanan SA, et al                               ARTICLE

Title:Radiographic detection of dental calculus.

Source:J Periodontol. 58:747-751, 1987

Type:Clinical

Rating: Good

Keywords:calculus, radiographs, sensitivity, specificity.

P:To quantify the sensitivity, specificity and observer error associated with radiographic detection of dental calculus on proximal surfaces of teeth in patients with severe periodontitis.

M&M:18 patients that required extraction of at least 3 teeth because of severe periodontitis participated in the study. Excessively rotated or malpositioned teeth were not included in the study. Radiographic presence of calculus was determined by two examiners. After tooth extractions teeth were prepared and examined microscopically for calculus.

R:275 proximal tooth surfaces and the corresponding radiographs were available for evaluation. Mean AL was 5.8mm.

Of the 153 surfaces with calculus noted visually, radiographically calculus was detected 43.8% (false negative 56.2%), (low sensitivity).

Of the 73 surfaces with calculus present radiographically, 91.8% were determined calculus present clinically.

Of the 160 surfaces assessed radiographically as calculus absent, 46.3% were verified by visual examination to have no calculus.

Radiographic evaluation of calculus was not an effective diagnostic method in most surfaces with thin or moderate deposits.

C:Conventional radiographs are a poor diagnostic method for detection of calculus. Radiographic analysis predicted calculus on less than half of the proximal surfaces where deposits were present visually.

Whatalveolar crest level represents bone loss on a bitewing radiograph??

Topic:Radiographic measurement of bone

Author: Hausman E., Allen K., Clerehugh V.                                ARTICLE

Title: What alveolar crest level on a bite wing radiograph represents bone loss?

Source: J Periodontol 1991;62;570-572

Type:RCT

Rating:Good

Keywords:bone level, radiographic interpretation

P: Compute the distance from the CEJ to the alveolar crest on radiographs at sites where there was no clinical loss of attachment.

M&M:

  • Bitewing radiographs were taken on 68 pts (13-14 years old). A second set of radiographs were taken 18 months later.

  • The radiographs were taken using a routine unstandardized clinical technique and were processed under standardized conditions using a Refrema processing machine.

  • At each radiographic examination probing attachment level measurements were made at the mesio-buccal surfaces of the first molar teeth. Only the sites with zero attachment loss (attachment at the level of the CEJ) at both baseline and at 18 months were included in this study. A total of 134 sites included in the study.

  • A computer program was developed to measure the CEJ-crest distance (mm) in a line parallel to the long axis of the tooth.

R: The mean radiographic CEJ- alveolar crest distance (mm) for the 134 sites with zero loss of clinical attachment was 1.11 ±0.37 mm. at the initial examination and 1.19 ±0.34 mm at the same sites examined 18 months later . The 95% confidence limits were 0.4 mm to 1.9 mm.

BL: No crestal bone loss is consistent with a range of CEJ- alveolar bone crest distance between 0.4 and 1.9 mm as evidenced on bitewing radiographs.

Are digital radiographs equivalent to conventional radiographs in revealing bone loss?

Topic:Radiographic Interpretation

Authors: Khocht A, Janal M, Harasty L, Chang K:                               ARTICLE

Title: Comparison of direct digital and conventioanl intraoral radiographs in detecting alveolar bone loss.

Source: J Am Dent Assoc 2003;134;1468-1475

Type:Clinical Study

Rating: Good

Keywords:conventional radiographs, digital radiographs

P: To compare direct digital (D) and conventional (C) radiographic estimates of alveolar bone under normal clinical use.

M&M:25 subjects with perio with age range b/w 18-65 years and had full set of PAs and BW for diagnostic purpose and tx planning. All subject had min of 15 teeth without any intraoral pathology or systemic dz. A long cone parallel technique was used to take PAs and a paper sleeve with biting tab was used for BW. Within 4 weeks, a second set PAs and BW was taken with digital system (Shick). The distance from the CEJ (surfaces with non-identifiable CEJs due to restorations or overlapping were excluded) to the interproximal alveolar crest (where the PDL space ends on the root surface) was measured. 3rd molars were excluded. One examiner measured with a plastic ruler on the C x-rays while another examiner measured the D x-rays. Overall % agreement of first and second readings in C x-rays was 99 and it was 92 for the D images. The examiners performed their measurements independently from each other. Each examiner measured the conventional or digital radiographs twice and took two sets of measurements for each subject. The examiners took the second set of measurements without having access to the initial set.

R: Examiner measured 857 PAs and 315 BW image sites match on both radiographic systems.

  • Measurements in the D images for BW averaged about 0.3mm greater bone loss than did C x-rays.

  • For BW, the difference between C x-rays and D was not found in all mouth sextants.

  • Rather,more bone loss was indicated by D x-rays only in the posterior mand region (BW); measures in the posterior maxillary region were similar between the two methods.

  • Measurements from C PA images showed more bone loss in all max sextants.

  • Categorical bone levels (normal<3 mm, early-to-moderate loss 4-6mm and advanced loss>7mm) were assigned to evaluate how each rx method revealed bone level and loss. Agreement between D and C x-rays in revealing bone levels as normal or having early-to-moderate loss was low (D x-rays revealed more early-to-moderate sites).

It seems that digital radiographs impart a constant addition of millimeters to measures taken in the posterior mandibular.

C:  Under normal clinical use and without standardized film positioning, the average bone level measurements varied SS between C and D radiographs in certain regions of the mouth and that the disagreement between these two systems is influenced by the type of image PA or BW as well.

Cr: It is very difficult to take x-rays at the exact same angle with the sensor/film in the exact same place to compare measurements. Also, there may be error in calculating exactly where the CEJ is on the x-ray. The digital sensor is a different size, not flexible, and can be more difficult to position than conventional films. Having the USB cord attached to the digital sensor may interfere with subjects biting down on the BW tabs.

Topic:radiographic alterations

Authors: BruderG, Casale J, Goren, A, Friedman S                               NO ARTICLE

Title:Alteration of computer dental radiography images

Source:J Endod ;25;275-276 DOI: 10.1016/S0099-2399(99)80159-9

Rating: good

Keywords:radiography, distortion, digital images, alterations

P:to determine if digital images could be exported, altered, and then restored without visible signs of alteration

M&M:Images were exported from the computer radiography program, files were altered, then files were restored to the Schick format and printed

D:Digital images are relatively easy to export and alter with the use of a photo editing program. The need to implement technologies to safeguard digital radiography must be addressed to prevent potential abuses.

Are panoramic radiographs ever of value in periodontics?

Topic:Radiographs

Author: Kasaj A., Vasiliu Ch, et al.                               ARTICLE

Title:Assessment of alveolar bone loss and angular bony defects on panoramic radiographs

Source:Eur J Med Res. 2008 Jan 23;13(1):26-30

Type:Prospective study

Rating: Good

Keywords:Panoramic radiographs, angular bony defects, periodontal disease, bone loss

P: To investigate the prevalence and severity of alveolar bone loss and angular bony defects in randomly selected panoramic radiographs.

M&M: 500 panoramic radiographs of adult patients were studied. The mean age of the subjects was 51 years (range 20-80). Panoramic radiographs were placed on an x-ray viewer and evaluated by the same examiner. A calibrated periodontal probe was used to assess horizontal and vertical defects. If the interproximal projection of the CEJ was not identifiable, the apical termination of the restoration or crown margin was used for the measurements. A site was considered as having an angular bony defect if the bottom of the oblique radiolucency was located at least 2mm apical to the most coronal level of the interproximal alveolar bone.

R:

-In majority of subjects (86.7%) had some form of bone loss (horizontal and vertical).

Angular bony defects were found in 49.8 % of the patients.

-Angular defects were more present in the mandible than in the maxilla, most frequently in the mandibular posterior, and least frequently in the mandibular anterior.

-The mean depth of the angular bony defects was 6.0 mm with the greatest mean depth in the maxillary anterior area (6.8 mm).

-The mean M-D width of the intrabony defects was 2.44 mm, and was most pronounced in maxillary molars (3.1 mm).

-Female subjects exhibited a gradual increase of vertical defect with age whereas in male subjects vertical bone loss was most prevalent in the age group 40-60 years and decreased in the older age group (60% vs. 40%).

-Interradicular molar radiolucencies demonstrated 38.3 % of the subjects and were more frequent in the md (first molar) than mx.

C: This study demonstrated a high prevalence of angular bony defects found on panoramic radiographs suitable for regenerative periodontal treatment.

Topic:Radiography

Authors: Persson RE, Tzannetou S, Feloutzis AG, Brägger U, Persson GR, Lang NP                               NO ARTICLE

Title:Comparison between panoramic and intra-oral radiographs for the assessment of alveolar bone levels in a periodontal maintenance population

Source:J Clin Periodontol. 2003. 30(9):833-9

Type:Clinical study

Rating: Good

Keywords:orthopantomogram; radiographs; alveolar bone level; diagnosis; periodontitis; maintenance population; agreement

P:To assess the level of agreement between intraoral and panoramic radiograph for direct measurements of the distance between the CEJ and the alveolar bone level (BL) as well as the proportional relationship (CEJ-BL/root length) and to explore the symmetry between left and right sided measurements.

M&M: Intraoral (IO) and panoramic (OPG) images were obtained from 292 patients on maintenance therapy. Two examiners performed measurements on digitally processed images. The distance between the CEJ and marginal BL was measured at the mesial and distal aspects of each tooth. The distance between the CEJ and apex of the tooth was also measured. The proportional distance between CEJ and BL relative to the length of the root was calculated.

R:All measurements between the two examiners showed no statistically significant differences. The largest mean proportional difference between CEJ and BL was seen in the maxillary right posterior segment, suggesting advanced periodontal disease in these sites. The largest difference between IO and OPG reading was observed between measurements for the maxillary anterior sextant, while the smallest difference was seen in the mandibular anterior sextant.

C: The study suggests that BL measurements between IO and OPG radiographs are highly comparable. The mean differences observed for the distance CEJ-BL in proportion to root length were neither statistically nor clinically different. A significant degree of symmetry of alveolar bone loss between the left and right side of the dentition was also found.

When should cone beam computed tomography (CBCT) be used?

Topic:CBCT in dentistry

Authors: The American Dental Association Council on Scientific Affairs.                               NO ARTICLE

Title:The use of cone beam computed tomography in dentistry: An advisory statement from the American Dental Association Council on

Scientific Affairs.

Source:J Am Dent Assoc 2012;143;899-902
Type:Discussion

Rating: Good

Keywords:CBCT, ALARA

ADA Council on scientific affairs 2012: The use of CBCT in dentistry

CBCT imaging provides three-dimensional volumetric data construction of dental and associated maxillofacial structures with isotropic resolution and high dimensional accuracy.

A CBCT scanner uses a collimated x-ray source that produces a cone- or pyramid-shaped beam of x- radiation, which makes a single full or partial circular revolution around the patient, producing a sequence of discrete planar projection images using a digital detector. These two-dimensional images are reconstructed into a three-dimensional volume that can be viewed in a variety of ways, including cross-sectional images and volume renderings of the oral anatomy.

Although CBCT units produce a higher radiation dose than one would receive from a single traditional dental radiograph, the radiation dose delivered typically is less than that produced during a medical multichannel computed tomographic scan. CBCT radiation doses also vary widely according to the device used, x-ray energy and filtration, tolerance for image noise and motion artifacts and the size of the imaging area that is used to acquire volumetric data.

Principles for the safe use of dental and maxillofacial CBCT

– Should be used only after review of pt’s health, and imaging history and thorough clinical examination

– Should be used only after professional justification that the potential clinical benefits will outweigh the risks associated with exposure to ionizing radiation

-The clinician should prescribe traditional dental radiographs and CBCT scans only when he or she expects that the diagnostic yield will benefit patient care, enhance patient safety, sig- nificantly improve clinical outcomes or all of these.

-Should be considered as an adjunct to standard oral imaging modalities

ALARA(As-low-as-reasonably-achievable) principle

– Should take every precaution to reduce radiation dose and ensure the patient’s safety. The use of thyroid collars and lead aprons is recommended when they do not interfere with the examination.

– Regardless of the primary purpose for the selection of CBCT, the complete image data set must be interpreted by a qualified health care provider. The prescribing clinician should receive a thorough radiological report

– Dental practitioners who use CBCT devices must receive appropriate training and education in the safe use of CBCT imaging systems

– Facilities using CBCT systems should consult a health physicist to perform equipment performance and compliance evaluations initially at installation and then follow a schedule in compliance with local, state and federal requirements

– Staffs of facilities using CBCT should establish a quality control program. This program can be based on the manufacturer’s recommendations

Topic:Radiograph

Authors: Misch KA, Yi ES, Sarment DP:.                                ARTICLE

Title: Accuracy of cone beam computed tomography for periodontal defect measurements.

Source: J Periodontol. 2006 Jul;77(7):1261-6.

Type: Clinical study

Rating: Good

Keywords:Periodontal defect, CBCT

P:To compare linear measurements of periodontal defects using CBCT to traditional methods.

M&M: 2 human dry cadaver skulls with existing horizontal bone loss up to 20% were examined. Infrabony buccal, lingual, and interproximal defects with varying width and height were created with a bur in mandibular molar and premolar regions. Grooves were also placed vertically into the roots from the CEJ to the depth of defect. Gutta percha cones were superglued into the grooves. CBCT (i-cat) and PA radiographs were taken.

Measurements were taken from A) CEJ-depth of pocket, B) CEJ to alveolar crest, C) width of the defect. Impressions of the defects were taken, and all measurements were compared to electronic caliper measurements. The accuracy of impression and caliper measurements were verified using another set of defects with known height and width prepared in cast acrylic blocks. Statistical analysis was done.

R:

All infrabony defects were detected using CBCT and the probe.

Average correlation was 0.4 for direct, 0.53 for PA, 0.62 for CBCT and 0.95 for impressions.

Correlation varied b/w 0.09 and 0.99 within examiners.

NSSD between all the methods for CEJ-depth of pocket, detection of isolated IP defects, and for buccal and lingual defects.

C: CBCT measurements compared well to traditional methods, with the advantage of allowing observation of defects in all directions. Further investigation is needed.

Topic:CBCT vs intraoral radiographs

Authors:Vandenberghe B, Jacobs R, Yang J.                               ARTICLE

Title:Detection of periodontal bone loss using digital intraoral and cone beam computed tomography images: an in vitro assessment of bony and/or infrabony defects.

Source:Dentomaxillofac Radiol. 2008 Jul;37(5):252-60.

Type:Skull study

Rating:Good

Keywords:periodontium, crater, furcation involvement, intraoral radiography, cone beam computed tomography

P: To determine the diagnostic values of digital intraoral radiographs and cone beam CT (CBCT) in the determining bone loss, infrabony defects, and furcation involvement.
M&M: A cadaver head with upper and lower jaws fixed with 10% formalin and a dry skull covered with a soft tissue substitute were used to measure 71 selected periodontal defects. To assess bone levels, the CEJ was used as a reference point for the fixed jaws, and gutta-percha fixated onto the buccal and lingual of teeth for the dry skulls. Intraoral radiographs were obtained with standardized bite blocks. CBCT was obtained with I-CAT. For the CBCT the observation were made on a 5.2 mm panoramic reconstruction view and on .4mm thick cross-sectional slices. First part of the study: 43 randomly selected sites with linear or vertical defects were chosen for radiographic and CBCT assessment of the bone loss and compared to the actual measurements. Second part of the study, 11 teeth containing vertical defects or furcation involvement was compared to actual measurements. The defects were categorized by 1, 2, 3 and 4 walls and the furcations by class 1, 2,3. Readings were performed by 3 examiners a medical imaging master and PhD student, and two radiology faculty members.

R: No intra- or interobserver effect was found. No significant differences were found when comparing the radiographs with those on the panoramic reconstruction image of the CBCT. The mean error for bone level measurements was 0.56 mm for radiographs, 0.47 mm for the CBCT panoramic view and 0.29 mm for the .4mm thick cross-sectional slices.SSD between the cross sectional slices and the radiographs. The detection of crater and furcation failed 29% and 44% with radiographs, and 0% with CBCT.

C: CBCT allowed more accurate assessment of periodontal bone loss.

What if the significance of the lamina dura?

Topic:Lamina Dura

Authors: Tibbetts J, Allen K, Hausmann E                               ARTICLE

Title:Effect of x-ray angulation on radiographic periodontal ligament space width

Source:J Periodontol 63: 114-117, 1992

Type:Clinical

Rating: Good

Keywords:Periodontal ligament/anatomy and histology; periodontal ligament/radiography.

P:To determine the influence of known changes in x-ray beam angulation anticipated under clinical conditions on the change in radiographic ligament space width. Radiographs of molars and incisors were studied to determine the influence of anatomical factors on changes associated with alteration in x-ray beam angulation

M&M:Pairs of radiographs were taken of incisor and molar locations in whole dried human skulls with known differences in x-ray beam angulation. To be acceptable, radiographs had to meet the following requirements: 1) no overlaps of contact areas of adjacent teeth, 2) visible interdental alveolar bone, 3) no cone-cut in the radiograph, 4) sufficient contrast to read any anatomic structures present. Baseline for vertical angulation was set perpendicular of the long axis of the tooth. For each tooth site, radiographs were taken at 2 vertical angulations: 1) perpendicular to tooth’s buccal surface 0° and 2) 10° off the perpendicular. 5 different horizontal angulations at each of the 2 indicated vertical angulations 1) baseline 0°, 2) -3° and -6° from the perpendicular, 3) +3° and +6° from the perpendicular. Replicate radiographs were taken at 0° and at each of the 2 vertical angulations. The radiographs were converted to digitized images and PDL width measurements were made utilizing a computer program. Data were analyzed separately for the incisor and molar sites.

R:The variation between the mean difference of baseline measurements was compared with that of discrepant-angle combinations, 10/20 pairs of radiographs which differed in horizontal angle only were significantly different from results of baseline replicates. 2/5 groups of pairs of radiographs which differed in vertical angle only were significantly different from results of baseline replicates. 11/20 groups of pairs of radiographs which differed in both vertical and horizontal angulation were significantly different from results of baseline replicates. Mean PDL width differences for incisor locations were SS from the mean baseline PDL width difference, posterior PDL width difference showed no statistical variation from the mean baseline width difference

C:Changes in x-ray angulation resulted in a SS change in radiographic PDL width at incisor locations, no such significant effect was found at molar locations. At molar area, thick bone overlying PDL will tend to reduce the difference in density seen on the radiograph of the ligament space and adjacent interproximal bone. It is suggested the radiographs should be taken with controlled projection geometry when clinical interpretation of change in PDL width is desired.

Topic:Lamina dura

Author:Greenstein G, Polson A, et al                              ARTICLE

Title:Associations between crestal lamina dura and periodontal status.

Source: J. Periodontol. 52:362-366, 1981.

Type:RCT

Rating:Good

Keywords:lamina dura, radiographic diagnosis, bitewing radiographs

P:To investigate the association between the radiographic presence of crestal lamina dura and the clinical periodontal status of the corresponding interdental area.

M&M:

  • 90 pts (53F, 37M; 21-45 years old) had 4 interproximal locations evaluated.

  • Sites were scored for visual inflammation, BOP, presence of PD> 3mm, and loss of attachment.

  • Bitewings and full mouthseries radiographs taken.

  • The radiographs were examined and scored for the presence or absence on an intact crestal lamina dura.

R:  NSSD correlations were obtained between PA radiographs, presence of lamina dura and inflammation, PD, or attachment loss. On bitewings, there was a SSD between presence of crestal lamina dura and inflammation (81.9%) versus absence of crestal lamina dura and inflammation (72.5%).No SSD with the other parameters and bitewings. However, there were significant discrepancies on whether the crestal lamina dura was present (agreed 24% of the time) and agreed 89% of the time when absent.

BL: Radiographically, the crestal lamina dura did not appear to be related to the presence or absence of clinical inflammation, BOP, presence of pockets, or loss of attachment.

Can radiographs be used to detect

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