125. ORAL SURGERY / PERIODONTICS

# 126 RESTORATIVE / PERIODONTICS                                    

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# 125 ORAL SURGERY / PERIODONTICS

  1. Should the recommendation for third molar removal be made to every patient? Are these teeth more susceptible to periodontal breakdown? What affect does third molar removal have on the periodontium of adjacent teeth?

  1. Osborne WH, Snyder AJ, Tempel TR. Attachment levels and crevicular depths at the distal of mandibular second molars following removal of adjacent third molars. J Periodontol. 53:93-95, 1982.

  2. Kugelberg CF, et al. Periodontal healing two and four years after impacted lower third molar surgery. A comparative retrospective study. Int J Oral Surg 1990; 19: 341-345

  3. Giglio J, Gunsolley J, Laskin D, Short K. Effect of removing impacted third molars on plaque and gingival indices. J Oral Maxillofac Surg 1994; 52: 584-587

  4. Kan KW, Liu JKS, et al. Residual periodontal defects distal to the mandibular second molar 6-36 months after impacted third molar extraction. J Clin Periodontol 29:1004-1011, 2002.

  1. If patients are having maxillofacial surgery, are there any particular concerns with the periodontium about which they should be advised? Do osteotomy cuts damage the periodontium?

  1. Schultes G, Gaggl A, Karcher H. Periodontal disease associated with interdental osteotomies after orthognathic surgery. J Oral Maxillofac Surg 56:414-417,1998.

  2. Foushee D, et al. Effects of mandibular orthognathic treatment on mucogingival tissues. J. Periodontol. 56:727- , 1985.

# 126  Restorative Dentistry / Periodontics

Non-Implant Supported Fixed and Removable Prosthesis

  1. Discuss periodontist/restorative dentist interactions, especially with regard to treatment planning and maintenance. What factors are important to consider for long term success? Does the position, material or span of replaced dentition change any of these factors? What common complications are seen with fixed restorations?

  1. Maynard J., Wilson, R: Physiologic dimensions of the periodontium significant to the restorative dentist. J Periodontol 50:170, 1979

  2. Gracis, S et al: Biological integration of aesthetic restorations: Factors influencing appearance and long –term success. Periodontol 2000 27:29-44, 2001

  3. Kois, J: The restorative-periodontal interface: Biological parameters. Periodontol 2000 11:29-38, 1996

  4. Nyman S, Lindhe J. A longitudinal study of combined periodontal and prosthetic treatment of patients with advanced periodontal disease. J. Periodontol. 50:163-169, 1979.

  5. Goodacre C. et al. Clinical complications in fixed prosthodontics. J Prosthet Dent. 2003 Jul;90(1):31-41

  1. What are some considerations for the margin placement and morphology of dental restorations? How can this affect the periodontium? Can dental treatment of the coronal aspect of a tooth cause changes in the clinical attachment? In the microbial population? How does the periodontal condition of a tooth affect the restorative plan?

  1. Jeffcoat MK, Howell TH : Alveolar bone destruction due to overhanging amalgam in periodontal disease. J. Periodontol. 51:599-602, 1980.

  2. Lang N, Keil R, Anderhalden K : Clinical and microbiological effects of subgingival restorations with overhanging or clinically perfect margins. J. Clin. Periodontol. 10:563-578,1983.

  3. Pack ARC, Croxhead LJ, McDonald BW : The prevalence of overhanging margins in posterior amalgam restorations and periodontal consequences. J. Clin Periodontol.17:145-152, 1990.

  4. Rodriguez-Ferrer HJ, Strahn JD, Newman HN. Effect on gingival health of removing overhanging margins of interproximal subgingival amalgam restorations. J Clin Perio 7:457-462, 1980.

  5. Wang, H et al: The relationship between restoration and furcation involvement on molar teeth. J Periodontol 64:302-305, 1993

  6. Silness J : Periodontal conditions in patients treated with dental bridges. II. The influence of full and partial crowns on plaque accumulation, development of gingivitis and pocket formation. J.Periodontal Res. 5:219-224, 1970.

  7. Valderhaug J et al: Oral hygiene, periodontal conditions and carious lesions in patients treated with dental bridges. J Clin Periodontol. 1993 Aug;20(7):482-9.

  8. Nyman S, Ericsson I : The capacity of reduced periodontal tissues to support fixed bridgework. J. Clin. Periodontol. 9:409-414, 1982.

  9. Lee HE, Wang CH, Chang GL, Chen TY. Stress analysis of four-unit fixed bridges on abutment teeth with reduced periodontal support. J Oral Rehab 1995; 22:705-710. 

  1. Describe the crown lengthening procedure. What anatomic considerations must be taken into account? How constant is the biologic width? Is it the same for all patients? How do we determine whether or not bone or soft tissue needs to be removed? What flap design would be needed for clinical crown lengthening?

  1. Gargiulo A, Wentz F & Orban B: Dimensions and relations of the dentogingival junction in humans. J. Periodontol. 32:261-267, 1961.

  2. Barboza E et al. Supracrestal Gingival Tissue Measurement in Healthy Human Periodontium. Int J Periodontics Restorative Dent 2008,28:55-61.

  3. Perez J et al: Clinical Evaluation of the supraosseous gingivae before and after crown lengthening. J Periodontol 2007:78:1023-1030

  4. Herrero F, Scott J, Maropois P, Yukna R A. Clinical comparison of desired versus actual amount of surgical crown lengthening. J Periodontol 1995:66:568-571.

  5. Bragger, et al: Surgical lengthening of the clinical crown. J Clin Periodontol 19:58-63, 1992

  6. Pontoriero R et al: Surgical crown lengthening: A 12-month clinical wound healing study. J Periodontol 72:841-8, 2001

  7. Deas D., et al: Osseous surgery for crown lengthening: A six month clinical study. J Periodontol, 2004 Sep. 75(9):1288-94

  8. Tarnow DP, Magner AW, Fletcher P. The effect of the distance from the contact point to the crest of the bone on the presence or absence of the interproximal dental papilla. J Periodontol 1992; 12: 995-996

  1. How does esthetic crown lengthening differ from functional crown lengthening? What treatment parameters must be considered prior to surgery? What information about the final restoration is needed to correctly plan? Are there differences if restorations are involved? When is periodontal treatment not enough?

  1. Jorgensen M, Sowzari H: Aesthetic crown lengthening. Periodontol 2000 27:45-58, 2001

  2. Garber, D., Salama M: The aesthetic smile: Diagnosis and treatment. Periodontol 2000 11-28, 1996

  3. Robbins JW: Differential diagnosis and treatment of excess gingival display. Pract Periodont Aesthet Dent. 11(2):265-272, 1999

  4. Wise MD : Stability of gingival crest after surgery and before anterior crown placement. J Prosthet Dent 1985; 53: 20-23

  5. Carnevale G, di Febo G, Fuzzi M. A retrospective analysis of the perio-prosthetic aspect of teeth re-prepared during periodontal surgery. J Clin Perio 17:313-316,1990.

  1. What are the ways in which restorative materials can affect gingival tissue? How would you address changes in oral mucosa that appear soon after a restoration? What if it is a new patient and an older restoration?

  1. Dragoo MR, Williams GB : Periodontal tissue reactions to restorative procedures. Part I. Int. J. Perio. Rest. Dent. 1(1):9-24, 1981.

  2. Dragoo MR, Williams GB : Periodontal tissue reactions to restorative procedures. Part II Int. J. Perio. Rest. Dent. 2(2):35-46, 1982. 

  1. What important considerations must be taken in to account when designing RDPs for patients with periodontally compromised dentition? How does the tissue react on perio healthy patients?

  1. Petridis H, Hempton TJ. Periodontal considerations in removable partial denture treatment: a review of the literature. Int J Prosthodont. 2001 Mar-Apr;14(2):164-72.

  2. Bissada N, et al. Gingival response to various types of removable partial dentures. J Periodontol. 45:651-659, 1974.

  3. Wright PS, Hellyer PH. Gingival recession related to removable partial dentures in older patients. J Prosthet Dent 74:602-607,1995.

  4. Hansen C, Clear K, La Mar S. Removable partial denture design considerations where periodontally compromised teeth exist. Int J Periodont Rest Dent 1997; 17: 89-93.

  1. What kind of splints exist? How does splinting affect the periodontium? What is the relationship between splinting and mobility? When do we offer splinting as part of restorative treatment?

  1. Glickman I, Stein RS, Smulow JB. The effect of increased functional forces upon the periodontium of splinted and non-splinted teeth. J. Periodontol. 32:290 – , 1961.

  2. Kegel W, Selipsky H, Phillips C : The effect of splinting on tooth mobility. I. During initial therapy. J. Clin. Periodontol. 6:45- , 1979.

  3. Serio FG. Clinical rationale for tooth stabilization and splinting. Dent Clin NA 43:1-6,1999.

  1. Are tooth-retained overdentures a valid treatment option? For whom would this be a good option? What complications can be associated with this therapy?

  1. Lauciello, F Ciancio, L: Overdenture therapy: A longitudinal report. Int J Perio Rest Dent. 4:63, 1985

125  ORAL SURGERY / PERIODONTICS

  1. Should the recommendation for third molar removal be made to every patient? Are these teeth more susceptible to periodontal breakdown? What affect does third molar removal have on the periodontium of adjacent teeth?

Osborne 1982                    ARTICLE
Purpose:  To determine whether definitive root planing and curettage would influence the periodontal attachment and crevicular depth on the distal of second molars, following removal of impacted and partially erupted 3rd molars.
Materials and methods:  18 pts (18-25 years old) with similar bilateral impactions classified as either bony or soft tissue impaction or as partially erupted.  PD measured at distobuccal, mid-distal and distolingual of 2nd molars. CAL was measured from cusp tips and marginal ridge to base of pocket.  Also assessed GI and PI.  On left side (test side), the distal root of the 2nd molar was planed and the tissue curetted and sutured after extraction of 3rd molars.  On the right side (control side), neither curettage nor root planing was done following 3d molar extraction.  Measurements, indices, impressions, radiographs and clinical photographs were made pre-op, 3 months and 1 year after 3d molars removal (15/18 returned for 3 month and 1 year follow-up).
Results:  NSSD were seen in PD average (3.8 control vs. 3.4 exp.), attachment level (5.5 control vs. 4.8 exp.), GI or PI.  The results were the same for all the three classes (bony impactions, tissue impactions, and partially erupted) of third molars.
Conclusion: The results of this study support the findings of Ash that root planing of adjacent 2nd molars is of little value in reducing post-op crevice or inducing reattachment.  The best means of preserving periodontal attachment may be the removal of 3rd molars at an early stage of tooth development.

Kugelberg 1990                    ARTICLE                   perio status of second molars
Purpose: To compare the periodontal condition of the adjacent 2nd molar 2 and 4 years after impacted mandibular 3rd molar extraction with special emphasis on age.
Materials and methods:

  1. 51 subjects (23M, 28F, 17-53 years old) selected at random from the retrospective survey.

  2. The patients were examined at 2 and 4 years after impacted mandibular 3rd molar extractions for PI, GI, PD, and radiographic measurements of proximal bone level (BL) and intrabony (IB) defect depth.

  3. The patients were divided into two groups for < 25 years old and > 25 years old.

  4. Only PDs greater than 3mm were recorded. PDs were divided into two groups: 6mm, and 7mm.

  5. The intrabony defects were measured on PA xrays that were taken with and without a perio probe placed in the deepest part of the defect (standarized). The depth of the defect was measured from the CEJ to the bottom of the defect on the PA film (with the probe in place) with a transparent ruler.

Results: 

  1. NSSD in the three clinical variables between 2 and 4 years. 

  2. At 4 years, 25% of  < 25 years old group and 52% of > 25 years old group had PD of 7mm or more on the distal of 2nd molars adjacent to the extraction sites. 

  3. NSSD in height of the alveolar crest on the distal surface was observed between 2 and 4 years for either group. 

  4. SSD between both groups for the alveolar height at both examinations. 

  5. Proximal bone levels showed SS improvement in the younger group.  46% of the young patients showed a decrease in IB defects, and 54% were unchanged. 

  6. None of the younger patients had increased in (IB) defects but 30% increased in IB in the older group (15% decreased).

  7. Intrabony defects 4mm in subjects < 25 yrs were recorded in 17% of the cases 2 years post-op, while present only in 4% of the cases 4 yrs post-op. The older group were 41% after 2 yrs and 44% after 4 yrs.

  8. Mean age for decreased PD was 23.5, unchanged 27.8 and increases in the PD depth the mean was 33 years. 

  9. All deteriorated cases were >26 years and 73% of improved cases were <25 years.

BL: Younger pts have a better resolution of defects after impacted 3rd molar extractions. Periodontal healing after mandibular 3rd molar extractions is a continuing process even after 2 years in young pts. When the need for extraction of the impacted 3rd molar can be foreseen, it may bebeneficial to perform the procedure at a younger age, specifically under 25 years old

Giglio 1994                    NO ARTICLE
P: To investigate the effect of removal of partially erupted mandibular 3rd molars on the plaque & gingival indices of other teeth.
M&M: 60 pts were assigned to 3 groups. Group 1 (Ctrl) had 3rd molars congenitally missing or previously removed, group 2 had asymptomatic, partially erupted 3rd molars, and group 3 was experiencing acute pain associated with a partially erupted 3rd molar. None of the pts were under periodontal maintenance or active perio tx. PII & GI were recorded in all 4 quads before and 6 weeks after surgery. No OHI were given.
R/Disc: Both GI and Pl improved in the symptomatic group while only the Pl improved in the asymptomatic group. Neither of the test groups scored as low as the control group post-op. This could be either due to a possible bias in the ctrl group toward better OH, or to the fact that healing was not yet complete influencing the pts ability to perform proper OH. Data from the 2nd molar adjacent to the sx site was analyzed separately showing that these alone were not responsible for the mean score improvement.
BL: The removal of impacted teeth may provide some benefit in terms of improved gingival health by reducing the plaque index.
Cr: short follow-up period

Kan 2002                   ARTICLE
P: 1) describe the periodontal conditions and other associated features of mandibular 2nd molars after surgical extraction of impacted 3rd molars.
2) identify the characteristics of impaction patterns which were associated with persistent post-extraction periodontal problems of these 2nd molars.
M&M: List of patients that had undergone extraction within a 30-month period was generated from the hospital’s computerized records, in the University of Hong Kong.
Eruption pattern of the 3rd molars and patient data (gender, age, time since extraction, smoking habits and history of scaling since the extraction) were recorded.The pre-extraction panoramic radiograph was studied and the impaction pattern of the 3rd molars and the presence of a crestal radiolucency indicating loss of crestal bone between the mandibular 2nd and 3rd molar were recorded.  Community Periodontal Index (CPI) protocol and the specific clinical condition of the subject mand 2nd molar (PD, Rec, BOP, suppuration on probing (SOP), tooth mobility and furc involvement) were assessed by two calibrated examiners. Plaque control and presence of caries lesion or a restoration at distal surface of the subject tooth were also recorded.
Results: 158 were examined in the study out of the 321 cases sampled initially from the computer list. 39% of patients were men and mean age 27.7 years. 77% had never smoked, 18% were current smokers and 5% former smokers. 67% had history of scaling after extraction, 49% had left 3rd molars extraction and 65% were partially erupted. 76% were classified as mesio-angular impactions and 18% were found to exhibit crestal radiolucency on the pre-extraction radiograph. The % of subjects having a highest CPI score of 2,3 or 4 were 53%, 41% and 6% respectively. Periodontal conditions of Mand 2nd molar 6-36 months following surgical extraction of adjacent impacted 3rd molar (n=156)

Surface

PPD (mean)

Rec (mean)

D

5.4

0.8

96

5

(SOP) Suppuration on probing 

Plaque was detectable on the distal surface of 87% of subject teeth, 1% showed furcation involvement, 3% had Grade I mobility and 1% Grade II. 6% had caries on the distal and 4% restoration.
PD was correlated with plaque detection at the distal of the 2nd molar and presence of crestal radiolucency. No association between PD distal of 2ndmolar and the length of time since surgical extraction of the 3rd molars.
Conclusion: Periodontal breakdown initiated and established on the distal surface of a mandibular second molar in the vicinity of a ‘mesio-angular’ impacted third molar evidenced by pre-extraction crestal radiolucency in association with inadequate plaque control after extraction can predispose to a persistent localized periodontal problem.

  1. If patients are having maxillofacial surgery, are there any particular concerns with the periodontium about which they should be advised? Do osteotomy cuts damage the periodontium?

Schultes 1998                     ARTICLE
Purpose: To evaluate the periodontal situation near interdental osteotomies after orthognathic surgery.
Materials and methods: 
30 patients with Class II malocclusion were studied 4-10 years after orthognathic surgery and orthodontic treatment.
15 anterior maxillary osteotomies, 10 sagittal maxillary splits, 9 Le Fort I osteotomies and 8 anterior mandibular segmental osteotomies were evaluated.
10 patients received ortho before the surgery and 20 patients had orthognathic surgery only.
Panoramic and periapical radiographs were made of the osteotomy region for every patient and the periodontal status was assessed.
A reduction in bone mass of 1/3 of the root length was classified as marginal superficial periodontitis and a further reduction as profound marginal periodontitis.
Post-op tooth loss was confirmed by comparison with pre-op radiographs. Lateral root resorption at the osteotomy sites was recorded.
Results:
51 pathologic periodontal findings in the 74 segmental osteotomy sites.
Periodontal pockets were found in 35 cases and post-op tooth loss in 16 segmental regions.
Average of 1.1 teeth per patient lost because of segmental osteotomies. In addition, 1.2 teeth per segment showed severe damage to the periodontium.
Superficial periodontal lesions were found in 1.7% and deep periodontal lesions in 47.5% of the osteotomy sites. 22% of the osteotomy sites showed a loss of teeth.
Lateral root resorption was present in 15.3% of the osteotomy sites. In the ortho treated patients 7/10 showed apical root resorption of mandibular and maxillary anterior teeth.
BL: A high incidence of dental and periodontal trauma occurs in the region of segmental osteotomies after orthognathic surgery.

Foushee 1985                      ARTICLE
P: To determine if alterations in mucogingival status (recession, width of KG, width of attached gingiva) occur in mandibular anteriors and premolars in patients after chin repositioning (genioplasty)
M+M: 24 patients (12-34 years old, 18 F 6M) evaluated for Orthognathic therapy; orthodontic treatment was performed and then genioplasty with or without mandibular advancement. Pretreatment measurements only on the facial surfaces of mandibular anteriors and premolars: width of KG, PD, recession, and width of attached gingiva. Second evaluation was done between 3 months and 3 years after surgery. 21 patients analyzed statistically looking at centrals, canines, and premolars. 8 patients received maxillary Osteotomies, 6 patients had mandibular advancement, 10 patients had maxillary and mandibular surgeries. 16 / 24 had either mild or moderate gingival inflammation with no PDs > 4 mm preoperative.
R: After Orthognathic treatment: SS decrease in KG for mandibular anteriors (median change = -0.5 mm) but no change for premolars. SS decrease of attached gingival for all teeth after surgery (median change for canines and premolars = – 0.5 mm, median change for incisors= 0). 10 / 24 showed post-treatment recession (4 pts had 0.5mm or less, while 6 pts had 0.5 to 3 mm). 5/6 pts having significant recession post-treatment had mandibular advancement in addition to genioplasty.
BL: The pretreatment width of keratinized and/or attached tissue was not the critical factor in development of recession. Risk of recession increased when genioplasty was combined with mandibular advancement and occur at sites where KG and underlying bone appeared thin.
Cr: All pretreatment measurements were taken by one examiner, and all posttreatment measurements were taken by a different examiner and then they were calibrated and analyzed for agreement.

126  Restorative Dentistry / Periodontics
Non-Implant Supported Fixed and Removable

  1. Discuss periodontist/restorative dentist interactions, especially with regard to treatment planning and maintenance. What factors are important to consider for long term success? Does the position, material or span of replaced dentition change any of these factors? What common complications are seen with fixed restorations?

Maynard 1979                    ARTICLE
D: When treating patients, the objectives of restorative therapy must be clear. The first and most basic objective is preservation of the teeth. The attainment of this objective would be far less complex if it could be considered independent of restoration of function, comfort and esthetics, but such is not the case. The latter objectives usually require sophisticated restorative dentistry and often include restorations with intracrevicular margins. Although it is widely accepted that the best restorative margin is one that is placed coronal to marginal tissue, most restorations have margins in the gingival crevice, and permanent tissue damage is common. In attempting to reach his objective, the restorative dentist must remember the fundamental precept of the health professions, which is: Do no harm. Daily observation of the three physiologic dimensions permits the therapist to restore teeth with minimal injury to the periodontium.

Gracis 2001                    ARTICLE
P: To discuss factors that determines the esthetic and long term success of esthetic restorations.
D:
Anatomical consideration
Biologic Width: Many authors have highlighted the inevitability of penetrating the epithelial attachment during the prosthetic procedures without causing any irreversible damage. Therefore, nowadays, ‘‘true’’ biological width violation means the placement of a restorative margin in the connective tissue attachment.
Papilla: The height of the interproximal papilla depends not only on the bone architecture but also on the relative tooth proximity: the closer the crowns, the more accentuated the papilla because the soft tissues tend to be supported by the proximal contours of the crowns. When preparing a tooth, the tip of the bur should therefore follow the gingival margin or the anatomic
configuration of the cementoenamel junction.
Thin Biotype: More at risk of recession, place margins supragingival.
Root prominences: Must be recognized for presence of fenestrations or dehiscences,
contraindication to placing margins subgingivally.
Supra vs intracrevicular margins
Supragingival, are easier to temporize, take impressions off, allow assessment of the fit of the restoration, allow margin finishing and burnishing, and facilitate plaque removal. Intracrevicular restorations cause more periodontal problems; this might be due to defective margins, inaccurate fit, roughness of the tooth–restoration interface, improper crown contour, violation of the connective tissue attachment, and greater pathogenicity of the subgingival dental plaque.
Factors that may force the clinician to place a restoration margin intracrevicularly:
– Need to improve the resistance and retention form of a short clinical crown
– Presence of caries or restorations extending apical to the gingival margin
– Modification of the emergence profile
– Aesthetics.
Phase one should be done first, Intrasulcular preparations should be performed exclusively in presence of a healthy crevice: only when it is inflammation free is the gingival margin stable and less prone to recession and can be probed and packed more accurately. Therefore, an intracrevicular margin should be placed 0.2 to 0.5 mm apical to the free gingival
margin on the facial side. Interproximally, because the sulcus normally is deeper, the preparation can extend more apically to better support the soft tissues. Some authors suggest placing a retraction cord in the sulcus before finalizing the preparation.
This maneuver has two advantages: it highlights the base of the sulcus and therefore the ultimate limit of the preparation before causing irreversible damage, and it pushes the gingival margin outward and apically to better expose the unprepared tooth structure to be removed.
The sequence of clinical steps consists of:
– Tooth preparation to the gingival margin
– Placement of an extra-thin knitted retraction cord that displaces the gingiva outward and
apically
– Definitive margin preparation to the top of the cord achieving a new, more apical position.
Provisionals
Protect the prepared teeth, to reduce the sensitivity of the vital abutments, and to prevent tooth migration. They are also instrumental in developing the correct aesthetics, phonetics and occlusal scheme before fabrication of the definitive restoration. More importantly, well-contoured and well-fitting provisional restorations allow the periodontal tissues to stay or become healthy.
Special attention should be dedicated to the development of the proper emergence profile of the provisional prosthesis.
Impression technique
The impression technique can have a negative impact on the soft tissues around the abutments, even causing irreversible damage if the technique is not properly carried out. The objective of tissue retraction is to expose all of the prepared tooth structure and, possibly, a portion of the unprepared root beyond the margin by causing a horizontal and vertical displacement of themarginal gingiva. A single-cord technique is the least traumatic option and is normally employed when the sulcus is shallow and the margin is placed only minimally in the crevice. A double-cord technique is used when the sulcus is deeper. Root proximity may create severe problems in obtaining good impressions because there will not be enough space to accommodate the retraction cords and, subsequently, a proper thickness of impression material. The placement of cords in such restricted interproximal spaces
may cause irreversible damage. Possible solutions to this problem are: partial- instead of full-coverage restorations to
1.Avoid preparing and restoring the side of the tooth with the proximity problem
2.More apical placement of the restorative margin if the root trunk tapers apically or an
odontoplasty with a flame-shaped bur to increase the separation
3.Orthodontic movement to separate the teeth
4.Strategic extractions.
Choice of restoration depends on:
1.Tissue type,
2.Tooth vitality
3.Abutment integrity
4.Abutment height
5.Occlusal clearance for proper strength
6.Aesthetic needs of the patient
7.Parafunctional habits

Posts
Fiber posts are more esthetic, however, may flex which has been associated with loss of the cement lute marginal seal and microleakage. Metal posts are rigid but can negatively affect esthetics.

Preparation design
Preparation designs for full-coverage restorations may be classified into four distinct types:
– Feather-edge: Frequently used for gold crowns and porcelain and composite veneers, lack resistance, and can cause over contouring, use should be limited.
– Chamfer: Widely used because of ease of preparation, however, according to some authors, the thin metal collar may distort during the firing of porcelain, thus producing inaccurate margins. The visibility of the metal does not allow these crowns to be used in areas where the aesthetic demands are high
– Shoulder with bevel: It is more conservative than a full shoulder preparation, but the presence of the metal collar necessitates an intracrevicular preparation in aesthetic areas
– Shoulder: The shoulder is probably the most popular design because it is very easily read by the technician, and it allows sufficient bulk for porcelain to produce aesthetically pleasing restorations

Kois 1996                    ARTICLE
Purpose: To examine several biological parameters looking at the restorative-periodontal interface
Discussion: 

  • Bacterial plaque accumulation: Plaque retention depends on surface roughness and the surface energy of the restorative material. The short-term positive gingival response of provisional restorations may not be a good indicator of the long-term gingival health. Mechanical insults such as bands, cord and retraction clamps can disrupt JE and CTA. This might heal with a recession that will self correct in the future. Possibly prescribe CHX for 2-week regimen with OHI if indicated

  • Marginal integrity of restoration: Clinical parameters of what constitutes acceptable margin have never been established. Marginal wear or ill-fitting prosthesis might lead to gingival inflammation but not progression of perio dz. 62% of restorations have an opening of at least 200 μm, bacteria generally range from 1-5 μm. 

  • Coronal contour must mimic natural teeth. It’s unclear what the definition of over- and undercontoured actually is. As contour is increased in 0.5 mm increments to 1.5 mm greater than original tooth dimension, papillary bleeding increases. This can be a problem for both supra- and subgingival margins. Close root proximity increases the importance of interproximal contour. Slight deviations can compromise the gingival tissue. One should be able to pass an explorer through to sulcus. If not, overcontoured. 

  • Alloy sensitivity: Ni containing alloys greatest risk of hypersensitivity. Contact dermatitis is most common mode of adverse reaction.

  • Margin location: Subgingival margins tend to be worse for gingival health. Most critical factor appears to be relationship to supracrestal fiber attachment. If margin placed in biologic width, adverse long term health seen. Need to locate the base of the gingival sulcus; however, in varying degrees of inflammation, probe penetrates differently. The osseous scallop is greatest in the anterior and flattens as move to posterior. If do not follow this scallop, may violate the biologic width in one area and not another on the tooth. If the biologic width is violated, might have recession. This depends on biotype and tissue management. 

BL:The proper margin location of restoration relative to the alveolar bone is one of the critical parameter to ensure long-term gingival health

Nyman 1979                    ARTICLE
Purpose: To present the results of periodontal and prosthetic treatment of patients with advanced breakdown of the periodontal tissues.
Materials and methods: 299 individuals were divided in two groups. Group I:non-bridge treatment group (48 patients). A well-functioning dentition could be established with periodontal treatment only. Group II (251 patients): bridge treatment group. Prosthetic treatment was required subsequent to the treatment of periodontal tissues. Following the active phase of treatment, all patients were placed in a maintenance program which included recalls every 3 to 6 months. Patients of Group I have been followed up for 8 years and those of Group II for 5 to 8 years. Following initial treatment and then once a year, the following parameters were assessed: PI, GI, PD, AL, and marginal alveolar bone height. Also, the frequency of and the reasons for technical failures in the bridgework were assessed. 332 fixed bridges were analyzed.
Results: Final examination (8 year follow-up for Group I and 5 to 8 years for Group II) revealed that both groups maintained low plaque scores and gingival indices. In none of the treatment groups, PDs varied in a significant way during the course of the study. Bone level was maintained unchanged in both groups. The analysis of the 332 bridges regarding frequency and reasons for bridge failures revealed:  1) Loss of retention of retainer crowns from abutment teeth (11 bridges, 3.3%), 2) Fracture of bridge (7 bridges, 2.1%), 3) Fracture of abutment tooth (one tooth in 8 bridges, 2.4%).
Conclusion: Following periodontal treatment, periodontal health can be maintained in patients enrolled in a controlled OH program. Supportive periodontal therapy (SPT) in this study was equally effective for patients with bridge work. Severe reduction of periodontal support around abutments and differences in bridgework design did not influence the periodontal status. However, technical failures occurred in 26 out of 332 bridges. These failures appeared as loss of retention, fracture of bridgework, and fracture of abutments.

Goodacre 2003                    ARTICLE
Purpose: To identify the incidence of complications and the most common complications associated with single crowns, FPDs, all-ceramic crowns, resin-bonded prostheses, and posts and cores.
Materials and methods:
Medline and extensive hand search covered the last 50 years and focused on publications that contained clinical data regarding success, failure, and complications.
Results:
Most common single crown complications

Mean Incidence

Need for endodontic treatment

Porcelain Fracture

Loss of retention

Periodontal Disease

Caries

Most common fixed partial denture complications

Mean Incidence

Caries

18% of abutments / 8% prosthesis

Need for endodontic treatment

11% of abutments / 7% prosthesis

Loss of retention

Esthetics

Periodontal disease

Tooth fracture

Prosthesis Fracture

Porcelain Veneer fracture

Most common all -ceramic crown complications

Mean Incidence

Fracture

Loss of retention

Pulpal health

Caries

Periodontal disease

0.0% No significant changes

Most common resin-bonded prosthesis complications

Mean incidence

Debonding

Tooth discoloration

Caries

Porcelain fracture

Periodontal disease

0.0% No significant changes

Most common post and core complications

Mean incidence

Post loosening

Root fracture

Caries

Periodontal disease

  1. What are some considerations for the margin placement and morphology of dental restorations? How can this affect the periodontium? Can dental treatment of the coronal aspect of a tooth cause changes in the clinical attachment? In the microbial population? How does the periodontal condition of a tooth affect the restorative plan?

Jeffcoat 1980                    ARTICLE                           amalgam overhangs
P: Examine the effects of overhanging amalgams on the alveolar bone height in patients with periodontal disease.
M&M: Examined records of 4600 patients screened for Overhangs. 100 selected with contralateral controls (no overhangs). Overhangs classified as small (occupies< 20% interproximal space), medium (20-50%), large (> 50%). Patients classified as to perio Class I-IV (ADA). Bone loss compared to control measured from CEJ to crest divided by root length using
radiographs.

R:  71% greater bone loss on overhang side vs. control. Small overhangs did not result in SSD vs. control but larger overhangs result in more bone loss. For each periodontal disease type the bone loss around the experimental teeth exceeded the control (5.6% for class I, 6.7% for class II, 12% for class III).
BL: Bone loss from overhanging amalgams is due to plaque retention and inflammation due to impingement of the embrasure space

Lang  1983                    ARTICLE
P: To determine if placement of subgingival restorations with overhanging margins results in change in the subgingival microflora.
M&M: 9 dental students with gingival index scores < 0.1 (pts had SRP and OHI first) requiring 10 gold MOD onlays for caries control. All MOD onlays preps were made with margin 1.0 mm subG;. Each tooth had 2 restorations fabricated: one with clinically perfect margins and one with 1.0 mm proximal overhangs. In a cross-over study, half of the teeth (5) had onlays w/1 mm proximal overhangs for 19-27 weeks that  were then replaced by 5 onlays with perfect margins. Another 5 teeth had onlays with perfect margins placed first (8-24 wks) which were then replaced with the 1 mm overhang MOD onlays (12-27 wks). Patient cleaned normally, except NO IPx cleaning at the site of the onlays. Prior to and every 2-3 weeks after insertion, PI, GI, subG microbiological samples (paper point) and PD to the level of the proximal margin of gold onlay were recorded..
R/D: Without overhangs, no increase in BOP at sites (if overhangs placed first, by the end of 2nd experimental period BOP had resolved). With overhangs, both groups by end of experimental period were at 100% BOP and GI of 2 or 3. For PD, as GI increased, so did the measurement to the FGM. There was no change from margin to base of sulcus (pseudopocketing with inflammation). With overhangs; there no change in the amount of plaque found subG, but rather the subgingival flora began to resemble chronic perio, w/ increased Gram – anaerobic bacteria, black pigmented Bacteroides (1.6%-3.8%) and increased anaerobe facultative ratio. With clinically perfect margins a microflora characteristic of health or initial Gingivitis was observed. Pts individually had different time frames for developing this flora, indicating host resistance/susceptibility.
BL: Placement of restorations with overhanging subgingival margins result in a change of subgingival microflora to one that may be associated with periodontitis, which documents a potential mechanism for iatrogenic initiation of periodontal disease. Host susceptibility plays a role in the time frame of how long it took to shift to a more peridontopathic microflora

Pack 1990                    ARTICLE
P: To determine prevalence of overhanging margins and associated periodontal status in 100 patients with completed treatment by final year dental students.
M&M: 100 subjects. PD, BOP, and clinically detectable margins recorded on all posterior teeth, and BWs were taken. No attempt to determine size of overhangs.
R: 1319 teeth with 2117 restored surfaces were examined.
– Prevalence: 1186 restored surfaces (56%) had overhangs, 62% of all restored interproximal surfaces
– 62% of distal, 60% mesial, 35% buccal, and 40% of lingual restorations had overhanging margins
– 69% of distal, 54% of mesial restorations next to the edentulous space had overhanging margins
– PDs > 3 mm: 64.3% of overhangs, 23.1% for unrestored surfaces, and 49.2% for non- overhanging restorations
– BOP, 32% of pockets adjacent to overhangs bled on probing, 10.5% for un-restored and 21.6% for non-overhangs.
BL: Periodontal disease was more prone in the presence of poor margins. These overhangs significantly affected the periodontal status of the teeth.

Rodriguez-Ferrer 1980                    ARTICLE
Purpose: To resolve the influence of removal of subgingival overhanging margins on the healing of gingival tissues and to determine whether it should be carried out at the beginning or at the end of the initial phase of periodontal treatment.
M&M: 15 pts with early to advanced periodontitis and 52 proximal surfaces that had confirmed overhanging restorations (amalgam) after removal of subgingival calculus were selected. Test group: 26 overhangs were removed at the first visit (no palpable transition between tooth surface and restoration). Control group: 26 contralateral-paired overhangs were left untreated. Every surface was scored for GI, PI, and PD at 0, 4, 8, 12 wks. Pts received OHI and performed Bass technique, flossing, toothpick and a proxy brush.
Results: After initial exam, NSD was observed in any parameters between test and control groups. By 12 weeks there was a SD for all indices except PD comparing test and control. The greatest change in gingival responses was seen in the first four weeks. Many of the restorations became supragingival as the marginal tissues responded to therapy.
BL: Gingival inflammation is a constant finding in areas related to Class II subgingival amalgam restorations with overhanging margins. Gingival inflammation is due to plaque accumulation in relation to overhangs, which impedes OH. Overhangs should be removed as soon as possible during initial phase of periodontal treatment.

Wang 1993                    ARTICLE
P: Cross sectional study The primary aim was to determine the relationship of crowns, proximal restorations and furcation involvement, and Secondarily was to evaluate the influence of the tooth mobility and endo treatment.
M&M: 134 perio maintenance pt (62 M and 72 F) that had restored and non-restored teeth with or w/o furcation involvement on molar teeth. Most of the restoration margins were supragingival and placed about 5 years prior to the study. 1st and 2nd molar were examined for the absence of presence of crown type restorations, restorations involving proximal surface, endo tx, furcation involvement, mobility, AL.
Results: 373 of 771 Molars had furcation involvement and 362 had restorations or crowns. 113 were mobile and 37 had RCT. So, molars with crown or restoration had higher prevalence of furc involvement (P<0.01).
 Loss of attachment associated with restorations was marginal(p=0.051), with more loss shown in the maxilla. The diff in AL b/w restored and non-restored molars occurs mostly in the maxillary arch
BL: pts w/ crowns or interproximal restorations are more likely to have furcation involvement and more CAL loss even undergoing regular maintenance.
-self critique: causality cannot be shown by X-sectional studies

Silness 1970                    ARTICLE
P: To compare the periodontal condition of abutments and contralateral teeth in patients with
full and partial crowns used for retaining dental bridges.
M&M: 261 individuals, 242 abutment teeth were compared with 242 contralateral teeth in the same patients. Patients were divided into groups depending on receiving periodontal treatment and OHI or not, location of crown margins (sub-g and no sub-g) and type of crowns (full or partial). Instructed group (159 individuals): this group had received periodontal treatment, OHI instructions and reinforcement 2-6 years before the examination. Non-instructed group (102 individuals): this group had received no periodontal treatment and no OHI. So 4 groups were formed: 1) GROUP I: non-instructed patients, full crowns with sub-g margins, 2) GROUP II: instructed patients, full crowns with sub-g margins, 3) GROUP III: instructed patients, full crowns with no sub-g margins, 4) GROUP IV: instructed patients, partial crowns with no sub-g margins. GI, PI, PD and margin index (position of margin in relation to crest) were recorded.
R: Abutments with complete crowns with full coverage and sub-g margin showed larger
amount of deposits, more severe gingivitis and increased PD compared to contralateral teeth
whether or not patients were instructed on oral hygiene. In instructed patients, the periodontal
condition of abutments with complete or partial crowns with limited coverage and no sub-g margin did not differ significantly from those of control teeth.
BL: Abutment teeth with crowns with subgingival margins are associated with more severe
gingivitis, deeper PD, and increased accumulation of plaque, compared to the uncrowned
contralateral teeth even in patients who were instructed in oral hygiene methods.

Valderhaug 1993                    ARTICLE
P: The aim of the present study was to assess the level of oral hygiene, periodontal conditions, changes of alveolar bone level and prevalence of caries in a group of patients who had received regular oral prophylaxis following the insertion of fixed partial dentures. Differences of these indices when the crown margins initially were located sub-gingivally, at the gingiva or supragingivally were also recorded.
M&M: 102 patients received a total of 108 cast gold or gold/acrylic bond bridges on 343 abutment teeth. The rest of the teeth on the same jaw that received the restorations served as controls. Clinical and radiographic exams were done at baseline, 5, 10, 15 yrs. PI, GI, PD, were measured. Margins placed >1m below the gingival margins were considered sub-gingival. Bone loss was measured to the nearest 0.5mm. Maintenance was offered every 6 months for the first 10 years. Statistical analysis was done.
R: Data at 5 (88 pts), 10 (71 pts) and 15 years (55 pts) recorded. 16 pts had a new bridge made or extraction of an abutment tooth over time (15.7%). There was NSSD for PI between test and control. Pi increased for 21% to 27% during the 15 year observation period. GI 2 and 3 was more frequent on abutment teeth than control, and more frequent on crowns with sub-gingival margins. A slight increase in PD was observed at 5- years at the teeth with sub-gingival margins. At baseline, 79% of surfaces had PD <2mm, 4% had PD >4mm. At 15 years, 57% of sites were <2 mm, while 3% were >4mm. Buccal surfaces had always shallower PDs than the other 3 surfaces. Sub-gingival crown margins decreased from 64% at baseline to 36% at 15 yrs (more pronounced on buccal). Caries were recorded at 3.3% of the abutment teeth at 5th year, 10% at 10th year, and 12% at 15th year. NSSD in bone loss could be detected between the test and control teeth or between the different crown margins locations.
BL: patients who were seen for regular OH maintained healthy periodontal conditions and relatively low caries. Many subgingival margins were seen at the gingiva or supragingivally after 10 or 15 yr.

Nyman 1982                    ARTICLE
Purpose: To compare the calculated size of the PDL around abutment teeth with the size

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151-152. Furcation Therapy

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Rapid Search Topics:

Discuss the etiology, incidence, and distribution of furcation invasions. Discuss the diagnosis and prognosis of furcation invasions by tooth type and compare to single rooted teeth. What role does root anatomy play in the etiology and management of furcation defects?

  1. Waerhaug J. The furcation problem. Etiology, pathogenesis, diagnosis, therapy, and prognosis. J Clin Periodontol 7:73-95, 1980.

  2. Ross IF, Thompson RH: Furcation involvement in maxillary and mandibular molars. J. Periodontol. 51:450-454, 1980.

  3. Dunlap RM, Gher ME. Root surface measurements of the mandibular first molar. J Periodontol56:234-238, 1985.

  4. Gher MW Jr, Dunlap RW. Linear variation of the root surface area of the maxillary first molar. J Periodontol.1985;56(1):39-43.

  5. Hou G, Tsai CC. Types and dimensions of root trunk correlating with diagnosis of molar furcation involvements. J. Clin. Periodontol. 1997; 24: 129-135

  6. Ward C, Greenwell H, Wittwer JW, Drisko C. Furcation depth and interroot separation dimensions for 5 different tooth types. Int J Perio Rest Dent1999;19:251-257.

  7. PaolantonioM, Placido M, Scarano A, Piatelli A. Molar root furcation: Morphometric and morphologic analysis. Int J Perio Rest Dent 1998;18:489-501.

  8. Ross IF, Evanchik PA: Root fusion in molars: incidence and sex linkage. J Periodontol52:663-667,1981.

  9. Hou G, Tsai C, Huang J. Relationship between molar root fusion and localized periodontitis.J Periodontol 1997; 68: 313-319

  10. Bjorn AL, Hjort P: Bone loss of furcated mandibular molars. A longitudinal study. J. Clin. Periodontol. 9:402-408, 1982.

  11. Tal H: Relationship between the depth of furcal defects and alveolar bone loss. J Periodontol 53: 631-634, 1982.

  12. Mealey BL, Neubauer MF, Butzin CA, Waldrop TC. Use of furcal bone sounding to improve accuracy of furcation diagnosis. J Periodontol1994;65:649-657

  13. Wang HL, Burgett FG, Shyr Y. The relationship between restoration and furcation involvement on molar teeth. J Periodontol 1993;64:302-305.

  14. Joseph I, Varma BR, Mahalinga BK. Clinical significance of furcation anatomy of the maxillary first premolar: a biometric study on extracted teeth. J Periodontol 1996;67: 386-389.

  15. Booker BW 3rd, Loughlin DM. A morphologic study of the mesial root surface of the adolescent maxillary first bicuspid. J Periodontol. 1985 Nov;56(11):666-70.

  16. Howell MM, Cassingham RJ, Yukna RA. Relationship of maxillary molar root angulation and palatal vault height. J Periodontol. 57:25-28, 1986.

  17. Muller H-P, Eger T. Furcation diagnosis. J Clin Periodontol 1999;26:485-498.(Review)

Describe Cervical Enamel Projections (CEPs), their classification and discuss their correlation with furcation involvements.

  1. Masters DH, Hoskins S. Projections of cervical enamel in molar furcations. J Periodontol 35: 49-53, 1964.

  2. Machtei EE, Wasenstein SM, Peretz B, Laufer D. The relationship between cervical enamel projection and class II furcation defects in humans. Quintessence Int. 1997;28:315-320.

  3. Hou G-L, Tsai C-C. Cervical enamel projection and intermediate bifurcational ridge correlated with molar furcation involvements. J Periodontol1997;68:687-693.

FURCATION MANAGEMENT

Discuss debridement, tunneling and root amputations/hemisections for furcation management.

Debridement

  1. Bower RC: Furcation morphology relative to periodontal treatment – furcation entrance architecture. J. Periodontol. 50:23-27, 1979.

  2. Bower RC, Thompson R.: Furcation morphology relative to periodontal treatment – furcation root surface anatomy. J. Periodontol. 50:366-374, 1979.

  3. Otero-Cagide FJ, Long BA. Comparative in vitro effectiveness of closed root debridement with fine instruments on specific areas of mandibular first molar furcations. I. Root trunk and furcation entrance. J Periodontol1997;68:1093-1097.

  4. Otero-Cagide FJ, Long BA. Comparative in vitro effectiveness of closed root debridement with fine instruments on specific areas of mandibular first molar furcations. II. Fucation area. J Periodontol1997;68:1098-1101.

Tunneling

  1. Hellden LB, Elliot A, Steffensen B, et al. The prognosis of tunnel preparations in treatment of Class III furcations, a follow-up study. J. Periodontol. 60:182-187, 1989.

  2. Rudiger SG. Mandibular and maxillary furcation tunnel preparations – literature review and a case report. J Clin Periodontol 2001;28:1-8.

Root Amputation/Hemisection

  1. Carnevale, G., Pontoriero, R., Di Gebo, G: Long-term effects of root respective therapy in furcation – involved molars. A 10-year longitudinal study. J Clin Periodontol 25:209-214, 1998

  2. FugazzottoP., A comparison of the success of root resected molars and molar position implants in function in private practice: Results of up to 15 plus years. J Periodontol 2001 Aug; 72(8):1113-23

  3. Kinsel, R., et al: The treatment dilemma of the furcated molar: Root resection versus single-tooth implant restoration. A Literature review. Int J Oral Maxillofac Impls 13:322-332, 1998.

Review

  1. Cattabriga M, Pedrazzoli V, Wilson, Jr. TG. The conservative approach in the treatment of furcation lesions. Periodontol 2000 2000;22:133-153. (Review)

Is chemical root treatment of benefit in furcation therapy?

  1. Parashis AO, Mitsis FJ. Clinical evaluation of the effect of tetracycline root preparation on guided tissue regeneration in the treatment of Class II furcation defects. J Periodontol 1993; 64:133-136.

How successful are the use of barrier for furcation tx?

Furca Treatment – Barriers – Non-resorbable

  1. PontorieroR, et al. Guided tissue regeneration in degree II furcation -involved mandibular molars. A clinical study. J. Clin. Periodontol15:247-254, 1988.

  2. PontorieroR, Lindhe J. Guided tissue regeneration in the treatment of degree II furcations in maxillary molars. J Clin Periodontol 1995:22:756-763.

  3. Mellonig JT, Seamons BC, Gray JL, Towle HJ. Clinical evaluation of guided tissue regeneration in the treatment of grade II molar furcation invasions.Int J Perio Rest Dent 1994;14:255-271

  4. Pontoriero R, et al. Guided tissue regeneration in the treatment of furcation defects in mandibular molars. A clinical study of degree III involvements.J Clin Perio 16:170-4,1989.

  5. PontorieroR, Lindhe J.Guided tissue regeneration in the treatment of degree III furcation defects in maxillary molars.J Clin Periodontol. 1995 Oct;22(10):810-2.

Furca Treatment – Barriers – Absorbable

  1. Yukna CN, Yukna RA: Multi-center evaluation of absorbable collagen membrane for guided tissue regeneration in human Grade II furcations. J Periodontol1996; 67: 650-657.

  2. Hugoson A, Ravald N, Johard G, Teiwik A, Gottlow J: Treatment of class II furcation involvements in humans with bioresorbable and nonresorbable guided tissue regeneration barriers. A randomized multi-center study. J Periodontol 1995, 66:624-634.

  3. Rosen PS, Marks MH, Bowers GM. Regenerative therapy in the treatment of maxillary molar class II furcations: Case reports. Int J Perio Rest Dent1997;17:517-527.

Discuss the relative long-term effectiveness of various treatment modalities in the management of furcation invasions.

  1. Hamp SE, Nyman S, Lindhe J. Periodontal treatment of multirooted teeth. Results after 5 years. J Clin Periodontol. 1975; 2:126-135

  2. Kalkwarf KL, Kaldahl WB, Patil KD: Evaluation of furcation region response to periodontal therapy. J. Periodontol. 59:794-804, 1988.

  3. Muller H-P, Eger T: Managment of furcation-involved teeth. A retrospective analysis. J Periodontol 1995:22:911-917.

  4. Evans GH, Yukna RA, Gardiner DL, Cambre KM. Frequency of furcation closure with regenerative periodontal therapy. J West Soc Perio (Perio Abstracts) 1996;44:101-109 (Review)

Discuss the etiology, incidence, and distribution of furcation invasions. Discuss the diagnosis and prognosis of furcation invasions by tooth type and compare to single rooted teeth. What role does root anatomy play in the etiology and management of furcation defects?

Waerhaug 1980                     ARTICLE

Purpose: To find out to what extent functional forces and subgingival plaque are involved in the etiology of the furcation involvement, and furthermore, whether or not marginal gingivitis and increased mobility reflect the degree of loss of periodontal attachment.

Materials and methods: 34 max and 12 mand molars with furcation were extracted due to advanced destruction of the periodontal tissues in the furcation area. 20 single roots from molar root resections were also included. All patients had been under periodontal treatment for a few months to several years (sub-g scaling and/or periodontal surgery), and had good OH. Prior to extractions the teeth where evaluated for PI, GI, and mobility. Premature contacts were identified. A landmark was made on the tooth surface at the gingival margin. Following extraction, the teeth were stained and examined under the stereomicroscope. The attachment loss was measured on the different surfaces of the roots with a translucent measuring device with 11 diverging lines.

Results: Gingivitis was found adjacent to 27% of the surfaces, supragingival plaque was present on 26% of them, on 39% of the surfaces there was sub-g, but not supra-g plaque. The average attachment loss was 47.3% on the outer surfaces and 62.8% on those facing the furcation. The average loss of attachment on the outer surfaces was 47.7% in the gingivitis group and 48.2% in the non-gingivitis.

Correlation between downgrowth of sub-g plaque and attachment loss

Distance from the front of the plaque mass (plaque front) to the attachment fibers: average distance 0.8mm on outer surface (0.2-2.4) and average distance 0.91mm on surfaces facing the furcation (0.2-4). 34 teeth exhibited normal mobility and the average loss of attachment was 41% on outer surface and 52% on surface facing furcation. 18 teeth were slightly mobile and average loss of attachment was 47% and 64% respectively. Premature contacts in CO were observed in 26% of teeth and most patients gave a positive answer to the question “has the teeth ever been tender or sore”. BOP and pain on probing were clearly less common in pockets without plaque.

DISC:Conditions below the gingival margin are extremely difficult to predict from clinical examination. Subgingival plaque is common even in the absence of supragingival plaque in patients who have started efficient supra-g plaque control after supra-g plaque has formed. Subgingival plaque may cause an undetectable submarginal gingivitis and lead to attachment loss and furcation involvement. The pathogenesis of attachment loss in furcations is associated with the down growth of subgingival plaque. Supragingival plaque control is ineffective in pockets greater than 3 mm (i.e. supragingival plaque control is effective to 2.5 mm). Surgical elimination of deep pockets is necessary (greater than 3 mm). Mobility and attachment loss do not support the assumption that functional forces are involved in the etiology of furcations. Mobility is the result of attachment loss, not the cause and appears late in the development of furcations.

Conclusion-Until now common solution to furcation problem has been extraction. With the knowledge about its etiology, it should be possible to prevent its development and to some extent treat established cases.

Ross 1980                     ARTICLE                               incidence and distribution of furcation involveme

Purpose: To examine, compare, and evaluate furcation involvement in maxillary and mandibular molars.

Materials and methods:

  • 615 molars of 72 patients (47 F, 25 M, 25-71 yrs old) with generalized chronic periodontitis were examined for age, sex, # of molars present, # of molars with furcation involvement (FI) detected radiographically and clinically, # of molars without FI, # of molars treated surgically.

  • Inclusion criteria:

  • At least one maxillary or mandibular molar with radiographic or clinical evidence of FI

  • The molar w/ FI must be in contact with at least one opposing molar during vertical and horizontal mandibular movements.

  • There must be at least 3 max molars w/ or w/o FI, a minimum of two in one quadrant and one in the contralateral quadrant.

  • At least 3 mandibular molars w/ or w/o FI, a minimum of two in one quadrant and one in the contralateral quadrant.

  • Treatment varied, but in no instance, was osseous surgery performed.

Results:

  • FI is a common occurrence: 90% in the maxillary, 35% in the mandibular.

  • FI 3X more frequently in the max molars.

  • Teeth w/ FI functioned well for a long period of time (5-24 years).

  • FI in max molars is detected more frequently by RAs, while in mandibular molars it is detected more frequently by clinical exam.

Maxillary

Mandibular

FI by radiographic and clinical eval

FI by radiographic eval only

FI by clinical examination only

No FI by radiographic or clinical exam

BL: Furcation involvement is a common occurrence and both radiographs and clinical exams should be performed to detect its presence. Prognosis and treatment should be based upon many factors, not just the presence of furcation. Furcation involvement should not condemn a tooth to an unfavorable prognosis.

Dunlap 1984                     ARTICLE

P:To determine the linear variation of Root Surface Area (RSA) in 1- mm increments from the CEJ to the apex for the mandibular 1stmolars

M&M:20 extracted mandibular 1st molars. Coronal and apical sides of the sections were photographed and the circumference from the root was measured. Teeth with fused root sand obliterated CEJs due to caries or restorations were excluded.

R: The largest RSA and % total RSA values were located 4 to 7 mm apical to CEJ. 48.7% of the RSA was located in the coronal 6mm of total root length root (mean length 14.4mm). Root separation occurred 4 mm apical to CEJ with no teeth having a root trunk longer than 6mm. B and L root concavities were first present 0.7mm and 0.3mm apical to CEJ, respectively. The mean RSA of the mesial root was SSD greater than the distal root and both had greater RSA than the root trunks. Distal roots were always more conical in shape than mesial roots.70% of the teeth had an intermediate bifurcation ridge.

BL:Horizontal attachment loss of 5- 6mm affecting both B and L surfaces of mandibular 1st molars can result in a through and through furcation involvement.

Gher 1984                     ARTICLE                            location of furcation entrances

Purpose:To determine the variation of root surface area in 1mm increments from the CEJ to the apex of max 1st molar. Locations of furcation entrances, root separations and the roof of furcations were also determined.

Materials and methods: 20 maxillary molars were selected, only teeth with fused roots were excluded. After preparation teeth were sectioned in 1-mm increments and root surface area (RSA) for each section was determined.

Results/BL:Mean root length 13.6mm (10.5-16mm) and mean RSA 477mm2.

Maxillary first molar – mean distances of root structures apical to the CEJ

Furcation entrances

Root separations

Furcation root

Mesial 3.6 ± 0.8

Facial 4.2 ± 1.0

Diatal 4.8 ± 0.8

Mesiobuccal 5.0 ± 0.7

Distobuccal 5.5 ± 0.8

4.6 ± 0.6

17/20 teeth had the roots separated with 6mm from the CEJ.

% of RSA increased significantly in the furcation area from 7.53% to 8.8-10.1%.

11/20 teeth demonstrated dome or concavities in the roofs of the furcations and the other 9 teeth a trifurcation ridge.

Hou 1997                     ARTICLE                            furcation anatomy and dimensions

Purpose: To investigate the effect of vertical dimension & types of root trunks on the vertical & horizontal bone losses in molar furcations.

Materials and methods:

  • Extracted teeth: 70 mx 1st molars, 96 mx 2nd molars, 103 mn 1st molars, 97 mn 2nd molars. Measurements of mx molars included vert height of buccal root trunk (BRT), mesial root trunk (MRT), & distal root trunk (DRT). Mn molars –BRT & LRT (lingual). Classified as:

  • Type A –root trunk involving cervical 1/3 or less of root length;

  • Type B-cervical 1/3 to ½;

  • Type C-cervical 2/3 or greater.

Results:

Max 1st molar

Mand 2nd molar

Mand 1st Molar

Max 2nd Molar

Type A

20.85%

83.5%

38.1%

Type B

47.1%

60.8%

15.5%

52.6%

Type C

11.9%

18.4%

BL: Longer root trunks are more common on 2nd molars than 1stmolars

Ward 1999                     ARTICLE

P: To document mean, SD, & range of furcation depth & inter-root separation of 5 multi-rooted tooth types.

M&M: 273 multi-rooted teeth examined:Max 1st & 2ndM,1st PM & Mand 1st & 2nd M. No restorations into the furcation, no fused roots. Furcation measured at level of the furc dome, then 3 & 5 mm apical to it. Inter-root separation measured 3 & 5 mm apical to the dome. Teeth were examined using telescopic lenses with 2.6x magnification.

R:

Furcation Depth (mm)

Mean ± SD

Mean ± SD

Mean ± SD

Max

1stM

2ndM

1stPM

Buccal at dome

7.48± 0.85

6.69 ± 1.02

M-D at dome

6.67 ± 0.52

5.94 ± 0.48

3.54 ± 0.48

Mand

1stM

2ndM

B-L at dome

7.96 ± 0.68

7.46 ± 0.74

Inter-root Separation (mm)

Mean ± SD

Mean ± SD

Mean ± SD

Max

1stM

2ndM

1stPM

B 3 mm apical to dome

2.58 ± 0.61

1.92 ± 0.60

M 3 mm apical to dome

4.17 ± 0.67

3.89 ± 0.86

2.47 ± 0.55

D 3 mm apical to dome

4.48 ± 0.81

4.04 ± 0.79

2.58 ± 0.68

Mand

1stM

2ndM

B 3 mm apical dome

3.15 ± 0.56

2.54 ± 0.59

L 3 mm apical dome

2.95 ± 0.74

2.75 ± 0.60

D: Furc depth ↓ in an apical direction, except for the buccal furcation of max molars, due to flaring of the palatal root. In regenerative healing, this means that as vertical entrance height ↑, the amt of bone ↓. Since root tapers in apical direction, root circumference ↓, decreasing the amt of PDL cells available to re-populate the wound. For max molar buccal furcation, the amt of bone ↑ w/ increasing vertical height, but the amt of PDL cells ↓, due to apical root tapering.

Inter-root separation increased from the dome to 3 then 5 mm except for the lingual of mand 2nd M, due to convergence b/w the mandibular roots in this area (pincher-like curvature)

BL:Height, width & depth of furcation differ for each furcation. As such, optimal conditions for GTR are different for every furcation. Additional research needed to find critical furcation dimensions for GTR.

Paolantonio 1998                      ARTICLE

P:Morphometric and morphologic analysis of maxillary and mandibular first and second molars using three different techniques.

M&M:207 maxillary molars (105 first and 102 second molars) and 207 mandibular molars (110 first and 97 second molars) were measured; root length, radicular trunk length (RTL), mesiodistal(MDD) and buccolingual diameters (BLD) at the CEJ, inter-radicular angle (IRA**) width, and furcal roof area (FRA) were recorded.

Morphologic examination was carried out by stereo microscopy, light microscopy of undecalcified sections, and scanning electron microscopy.

R:Morphometric:

  • IRA width decrease from 1M to 2M in both arches, more pronounced in maxilla.

  • FRA is wider in 1M.

  • 1M longer roots & shorter radicular trunks than 2M.

  • MDD & BLD are greater in 1M.

  • + correlation FRA/IRA for each molar.

  • + correlation BLD/IRA in both max M.

  • inverse correlation IRA/RTL in max 1M.

  • NSS correlations for the other measurement.

Morphologic:

  • Width of furca entrance.

  • Long RT .

  • Concavities internal of roots in mandibular M and M-B root of maxillary M.

  • Furca roof, narrow and irregular shape dimples, holes & crevices.

  • Furca canal orifices coming out into larger depressions.

CL:This study showed the complexity of the furcation area with a large number of anatomic irregularities and plaque-retentive structures that could hamper adequate cleaning during periodontal treatment.
IRA**: this measure was assessed by drawing a line in the center of the cervical third of each root and measure the value of the angle between each pair of lines with a goniometer.

Ross and Evanchik 1981                     ARTICLE                   incidence and distribution ofroot fusion

P:to report the incidence and distribution of root fusion in molars.

M&M:Radiographic examination of 1340 molars from 170 patients. Any molar that had one root or whose roots were fused apical to the usual furcal position was considered a molar with fused roots.

R:Frequency of molar fusion

First molars

Second molars

Third molars

Overall

Maxillary

Mandibular

52.4%

Overall 29% of all molars were fused and 71% non-fused. Fusion occurs bilaterally with equal distribution. Females have more root fusion than males. Root fusion was more common in the maxilla (35%) than the mandible (24%). Furcation can be an important factor in determining the prognosis of a tooth. Usually these roots are shorter (contribute to an unfavorable crow-root ratio) and more likely to become mobile.

BL:29% of all molars had fused roots. Root fusion was more common in the maxilla and more from post to ant (3rd M > 2ndM > 1st M)

Hou 1997                     ARTICLE

P:  To examine the relationship between molar root fusions and localized periodontal disease.

M&M:  143 individuals (1109 molars) aged 23-68 years were examined for molar root fusion at diseased and healthy sites by periapical radiographs and clinical probing.  PD, CAL, GI, and Pl were measured. The molars with root fusions, intact marginal alveolar crest, and CAL ≤ 5mm was considered healthy.

R:  The prevalence of molar root fusions in males was 15.2% vs. 32.2% in females.  Max 2nd molars (51.8%), mand 2nd molars (32.3%), max 1st molars (5.7%), and mand 1st molars (0%).  Prevalence of root fusion in max molars is 28.7% and mand molars is 16.7%.  SSD was observed in GI, CAL, PD and Pl between diseased and healthy sites.  97.5% had bilateral symmetry of fused roots.  A majority of the diseased molars with root fusion exhibited deeper developmental grooves than the healthy molars.

BL: Females tend to have a higher rate of molar root fusion.  Deep developmental grooves and the less resistance to heavy occlusal loads and/or torque forces enhance the possibility of localized periodontitis at molars with root fusion

Bjorn 1982                     ARTICLE

Purpose:To obtain information on the prevalence of interradicular bone destruction in mandibular molars as well as the fate of involved molars in a population not included in any periodontal treatment program.

Materials and methods: 221 staff members of an industrial company in Sweden were utilized. Panoramic radiographs and bite-wings were examined. Furc involvement was diagnosed when there was visible interradicular bone destruction.

No clinical examination was performed. The amount of radiographic bone loss was estimated using a plastic ruler and classified in 5 categories:

  • 0no bone loss

  • 10-25%

  • 225-50%

  • 350-75%

  • 4more than 75%
    The total observation period was 13 years.

Results:The mean number of mand. molars/patient was 3.5 in 1965 and 3.3 13 years later. 15 individuals had lost all the remaining molars. The frequency of molars with interrradicular periodontitis increased from 18% to 32% during the study period.

9.5% of the furcated molars observed at the first examination was lost, 2.5% because of periodontal disease.

2ndand 3rd molars exhibited increased bone loss when compared to the 1st molars. The severity of bone loss increased with age.

Conclusion: Furcation involvement has evidently not played any dominant part in the loss of mandibular molars during this 13-year observation period. This does not imply that furc. involvement may not in the long rung jeopardize the retention of a tooth.

Tal 1982                     ARTICLE

Purpose: To determine whether there is any relationship between the depths of furcal defects and the amount of alveolar bone loss on the buccal and lingual aspects of 1st and 2nd molars in dry mandibles

Materials and methods:

  • 100 dry mandibles of South African tribe members of known sex, tribe and age (20 in each decade, between third and seventh decade; since no dental treatment on these skullsassume no OH education). The depths of furcal defects and the distances between the CEJ and alveolar bone crest were measured on 245 lingual and 235 buccal surfaces of 246 1st and 2nd molars; Class III FI excluded.

Results:

  • High correlation between depth of furcal defects and distance between the CEJ and alveolar crest, w/ higher correlation for first molars than for second molars.

  • For the same degree of vertical bone loss, buccal furcation defects are deeper than the lingual, and buccal furcation defects on 1stMolars are deeper than those on 2nd Molars.

BL: Bone loss is greater on the facial than the lingual and is greater in 1st molars. Also, when 5-6 mm probing depths are present, one should suspect a class III FI. The elimination of furcation disease is essential to the success of periodontal therapy. Detection of furcation involvement is an essential part of any complete oral examination.

Mealey 1994                     ARTICLE

P:To compare vertical and horizontal measurements of furcation invasions taken by probing prior to anesthesia, by bone sounding following anesthesia and by direct assessment after surgery debridement.

M&M:67 patients (42M, 25F), age 30-76 y.o. 276 furcations with vertical & horizontal depth were assessed at 3 separate time points. For the vertical dimension pre-anesthesia, measurements taken with a straight probe from FGM-flute, & then probe advanced until resistance noted. Horizontal dimension was taken with a Nabers probe from FGM-flute and then until resistance felt. After anesthesia, bone sounding performed. Direct measurements were taken during surgery (vertical: straight UNC probe from initial fluting of furcation to bony defect; horizontal: Nabers probe from flute to depth of bony defect into furcation). None of the subjects had 3rdmolars present.

R:Mean vertical (1.8mm) and horizontal (2.16mm) furcation depths prior anesthesia were sig less than surgical measurements (2.79mm & 3.65mm respect). Surgical vertical depth was exactly the same as pre-anesthesia probings in 42% of the furcations, within 1 mm in 72% and within 2 mm in 83%. Surgical horizontal depth was equal to pre anesthesia probing in 47% of furcation, within 1 mm in 68%, and within 2 mm in 77% of cases. Use of post-anesthesia sounding improved agreement in vertical measurements ranging from 59.5% to 93%. Sounding improved the agreement of horizontal measurements from 64%-88%. Vertical sounding provided the greatest improvement in diagnostic accuracy for the facial furcations of mandibular second molars. Horizontal sounding had the greatest beneficial effect for the distal furcation of maxillary second molars. The use of sounding sig improved the accuracy of the measurements, however, there was still a small percentage of horizontal measurements that were significantly underestimated.

BL:Sounding reduced the degree of underestimation in all furcation types.

Wang 1993                    ARTICLE                        the impact of restorative dentistry on furcation involvement

Purpose:To study the impact of crown (CR) or proximal restoration (RE) on furcation involvement (FI) in molar teeth.

Materials and methods: 134 maintenance patients who had molars with and without FI and restorations were selected from University of Michigan patient pool. The majority of the patients had restorations for at least 5 years prior to the study. Clinical evaluation included assessment for CR, RE, endodontic treatment, FI, mobility more than 0.5mm in bucco-lingual direction, AL and PD for six sites/tooth. Data were analyzed and statistical analysis was performed.

Results:

Frequency Table on complete data set (n=771)

Variable

Absence %

Presnece %

Crown placement

Class II restoration

Mobility

Furcation involvement

Endodontic Treatement

  • Molars with CR or RE had a significantly higher presence of FI than molars without restorations.

  • Relationship between restoration status of the molars and mobility was not significant while that of endodontic Tx was significant but with small sample size.

  • More probing AL was measured in molars with RE< FI and mobility than in molars without the occurrences. More AL was found in molars RE and CR especially in the maxilla.

Conclusions:

  • Molars with CR or RE had a higher prevalence of FI and greater AL than non-restored molars.

  • The difference in AL between restored and non-restored molars occurred mostly in the maxillary arch.

  • Mobility was found to be a significant factor for AL but not FI.

Joseph 1996                     ARTICLE

P:to determine the frequency of bifurcation, and to explore the anatomy of max 1st PMs.

M&M:examined 100 extracted max 1st PMs. Teeth w/ caries, restorations, or damage were excluded.

R:

  • Only 37% of the examined teeth had bifurcated roots, the remaining had fused roots 63%.

  • Proximity of the furcation to CEJ- 35% apical third, 38% at the middle third, 27% at the cervical third.

  • The mean furcation width was 0.7 mm, which is less than the blade width of Gracy curette.

  • Concavities were found on the M and D of the root trunk in all 100 teeth examined

  • Furcal concavity was also found in 62% of the teeth with bifurcated roots

Disc:According to Corn et al. (1980), as a rule, the prognosis for maxillary first premolar teeth with osseous defects in the inter-radicular area is poor.

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123-124. Interdisciplinary Problems: PERIODONTICS- ORTHODONTICS- PEDIATRIC DENTISTRY

HOME PERIO TOPICS 

ORTHODONTICS

  1. What effect do malposed teeth have on periodontal health?Can orthodontic therapy improve malposition? What affect does this have on the periodontium? What can patients expect during and after orthodontics?

  1. Ainamo J. Relationship between malalignment of the teeth and periodontal disease. Scand J Dent Res. 80:104-110, 1972.

  2. Chung C-H, et al. Comparison of microbial composition in the subginigval plaque of adult crowded versus non-crowded dental regions. Int J Ortho Orthognath Surg 15:321-330,2000.

  3. Artun J, Osterberg SK, Kokich VG. Long-term effect of thin interdental alveolar bone on periodontal health after orthodontic treatment. J. Periodontol. 57:341-346, 1986

  4. Brown IA. The effect of orthodontic therapy on certain types of periodontal defects. I. Clinical findings. J. Periodontol. 44:742-756, 1973.

  5. Kraal JH, et al. Periodontal conditions in patients after molar uprighting. J Prosthet Dent 43:156 – 1980.

  1. Can patients with periodontitis safely have orthodontics? What tooth movements can be offered for periodontally involved teeth? When can orthodontics be a detriment to periodontal health? How would this change how we treat or manage patients? If flap surgery is indicated, when should open flap debridement be utilized? Grafting? Osseous surgery?

  1. Ong MA, Wang H-L, Smith FN. Interrelationship between periodontics and adult orthodontics. J Clin Perio 25:271-277,1998. (Review)

  2. Ericsson I : The combined effects of plaque and physical stress on periodontal tissues. J. Clin. Periodontol. 13:918 -, 1986. (Review)

  3. Ericsson I, Thilander B, Lindhe J, Okamoto H. The effect of orthodontic tilting movements on the periodontal tissues of infected and non-infected dentitions in dogs. J Clin Perio 4:278 – 1977.

  4. Corrente G et al: Orthodontic Movement into Intrabony Defects in Patients with Advanced Periodontal Disease: A Clincial and Radiological Study. J Periodontol 2003;74:1104-1109

  5. Polson A, et al. Periodontal response after tooth movement into intrabony defects. J. Periodontol. 55:197-202, 1984.

  6. Cardaropoli D: Reconstruction of the maxillary midline papilla following a combined orthodontic-periodontic treatment in adult periodontal patients. J Clin Periodontol 2004; 31:79-84.

  7. Wennstrom J, Stokland B, Nyman S, Thilander B. Periodontal tissue response to orthodontic movement of teeth with infrabony pockets. Amer J Ortho Dento Orthop 1993; 103:313-319.

  8. Araujo M et al: Orthodontic movement in bone defects augmented with Bio-Oss. An experimental study in dogs. J Clin Periodontol 28:73-80,2001

  9. Melsen B, Agerback N, Markenstam G: Intrusion of incisors in adult patients with marginal bone loss. Am J Orthod Dent Orthoped. 96: 232 – 241, 1989.

  1. When should orthodontics be considered as an alternative to periodontal surgery? In which cases is this indicated? What are some considerations for teeth that undergo extrusion? When else might a fiberotomy be considered?

  1. Ingber JS. Forced eruption: Part I. A method of treating isolated one- and two-wall infrabony osseous defects. Rationale and case report. J. Periodontol. 45:199-206, 1974.

  2. Ingber J. Forced eruption. Part II. A method of treating nonrestorable teeth -periodontal and restorative considerations. J. Periodontol 47:203-216, 1976.

  3. Salama H, Salama M. The role of orthodontic extrusive remodeling in the enhancement of soft and hard tissue profiles prior to implant placement: a systematic approach to the management of extraction site defects. Int J Periodontics Restorative Dent. 1993 Aug;13(4):312-33.

  4. Bellamy L et al: using orthodontic intrusion of abraded incisors to facilitate restoration: The technique’s effects on alveolar bone level and root length. J Am Dent Assoc 2008;139;725-733

  5. Carvalho et al: Orthodontic extrusion with or without circumferential fiberotomy and root planing. Int J Periodontics Restorative Dent 2006; 26:87-93

  6. Taner T, Haydar B, Kavuvlu I, Korkmaz A. Short-term effects of fiberotomy on relapse of anterior crowding. Am J Ortho Dentofac Orthop 118:617-623,2000.

  1. How should extractions be managed in conjunction with orthodontic therapy? Are there any long term effects moving teeth into extraction sites? How can this theory of accelerated movement affect ortho therapy?

  1. Reed B, Polson AM, Subtelny JD. Long-term periodontal status of teeth moved into extraction sites. Am J Orthod Dent Orthoped. 88:205-, 1985.

  2. Hasler R, Schmid G, et al. A clinical comparison of the rate of maxillary canine retraction into healed and recent extraction sites – a pilot study. Euro J Orthod 1997;19: 711-719

  3. Liou E, Huang CS. Rapid canine retraction through distraction of the periodontal ligament. Am J Orthod Dentofac Orthop 1998; 114: 372-380.

  4. Ahn HW, Ohe JY, Lee SH, Park YG, Kim SJ. Timing of force application affects the rate of tooth movement into surgical alveolar defects with grafts in beagles. Am J Orthod Dentofacial Orthop. 2014 Apr;145(4):486-95.

  5. Wilcko MT, Wilcko WM, et al. Accelerated osteogenic orthodontics technique: a 1-stage surgically facilitated rapid orthodontic technique with alveolar augmentation. J Oral Maxillofac Surg. 2009 Oct;67(10):2149-59.

  1. What is the significance of keratinized tissue during orthodontic movement? What is the relationship between mucogingival problems and tooth position? What is the relationship between mucogingival problems and tooth movement? Is prophylactic gingival grafting ever indicated?

  1. Coatoam GW, et al. The width of keratinized gingiva during orthodontic treatment. Its significance and impact on periodontal status. J. Periodontol. 52:307-313, 1981.

  2. Edwards JG. The diastema, the frenum, the frenectomy: A clinical study. Amer J Orthod Dent Orthoped. 71: 489-508, 1977.

  3. Pini Prato, et al: Mucogingival interceptive surgery of buccally – erupted premolars in patients scheduled for orthodontic treatment I : A 7-year longitudinal study. J Periodontol 71:172-181, 2000

  4. Pini Prato et al: Mucogingival interceptive surgery of buccally-erupted premolars in patients scheduled for orthodontic treatment II: Surgically treated versus non-surgically treated versus non-surgically treated cases. J Periodontol 71:182-187, 2000

  5. Artun J, et al. Periodontal status of mandibular incisors after pronounced orthodontic advancement during adolescence: A follow-up evaluation. Am J Orth Dent Orthop 119:2-10,2001

  6. Karring T, et al. Bone regeneration in orthodontically produced alveolar bone dehiscences. J. Periodontal Res. 17:309-315, 1982.

  1. What specific challenges are encountered with impacted/unerupted permanent teeth? Are there different approaches based on where and how the tooth is impacted? How should these patients be managed? Are there long term issues with the periodontal health of these teeth?

  1. Kokich V: Surgical and orthodontic management of impacted maxillary canines. Am J Orthod Dentofac Orthoped 2004; 126: 278-283

  2. Artun J, Osterberg SK, Joondeph DR. Long-term periodontal status of labially erupted canines following orthodontic treatment. J Clin Periodontol. 13:856-861, 1986.

  3. Burden D, Mullally B, Robinson S. Palatally ectopic canines: Closed eruption versus open eruption. Am J Ortho Dento Orthop 115:640-644, 1999.

  4. Quiryen M, Op Heij DG, et al. Periodontal health of orthodontically extruded impacted teeth. J Periodontol 71:1708-1714, 2000.

  5. Crescini A et al: Combined Surgical and Orthodontic Approach to Reproduce the Physiologic Eruption Pattern in Impacted Canines: Report of 25 Patients Int J Periodontics Restorative Dent 2007; 27:529-537

  1. How are implants utilized in ortho therapy? Do TADs have the same healing pattern as other titanium based implants?

  1. McGuire M et al: Temporary anchorage devices for tooth movement: A review and case reports. J Periodontol, 2006;Oct:77(10)1613-24

  2. Wiechmann, D et al: Success rate of mini- and micro- implants used for orthodontic anchorage: A prospective clinical study. Clin Oral Impl Res 18, 2007;263-267

  3. Celenza F. Implant interactions with orthodontics. J Evid Based Dent Pract. 2012 Sep;12(3 Suppl):192-201.

Pediatric Dentistry / Periodontics

Discussion Topics

  1. What are some of the anatomical differences in the jaws and periodontium between children and adults? Is the evaluation, etiology, prevalence, and treatment of mucogingival defects different in children as compared to adults?

  1. Maynard GJ, Oschenbein C. Mucogingival problems, prevalence and therapy in children. J. Periodontol. 46:543-552, 1975.

  2. Powell RN, McEniery TM : A longitudinal study of isolated gingival recession in the mandibular central incisor region of children aged 6-8 years. J. Clin. Periodontol. 9:357-364, 1982.

  3. Person M, Linnartsson B : Improvement potential of isolated gingival recession in children. Swed. Dent. J. 10:45-51, 1986.

  4. Bimstein E, Eidelman E : Morphological changes in the attached and keratinized gingiva and gingival sulcus in the mixed dentition period. A 5-year longitudinal study. J. Clin. Periodontol. 15:175, 1988

  5. Andlin-SobockiA, Marcusson A, Persson,M : 3-year observations on gingival recession in mandibular incisors in children. J. Clin. Periodontol. 18:155-159, 1991.

  6. Addy M, Dummer PM, et al.. A study of the association of fraenal attachment, lip coverage, and vestibular depth with plaque and gingivitis. J Periodontol. 1987 Nov;58(11):752-7.

  1. Do periodontal diseases occur at the same rate and with the same frequency in children as in adults? What are some of the periodontal diseases that appear to be specific to children? Are there differences in the composition of microbial plaque in children as compared to adults?

  1. Position Paper. Periodontal diseases of children and adolescents. J Periodontol 67:57-62, 1996.

  2. ClerehughV, Tugnait A. Diagnosis and management of periodontal diseases in children and adolescents. Perio 2000 26:146-168, 2001

  3. Mombelli A, et al. Gingival health and gingivitis development during puberty. A 4 – year longitudinal study. J. Clin. Periodontol. 16:451-456, 1989.

  4. Mombelli A, Rutar A, Lang NP. Correlation of the periodontal status 6 years after puberty with clinical and microbiological conditions during puberty. J Clin Periodontol 22:300-305,1995.

  5. Bimstein E, Ram D, Naor R, Sela MN. The composition of subgingival microflora in two groups of children with and without primary dentition alveolar bone loss. Pediatric Dent 18:42-47, 1996.

  6. Kargul B, Tanboga I, Ergeneli S, Karakoc F, Dagli E. Inhaler medication effects on saliva and plaque pH in asthmatic children. J Clin Pediatric Dent 22:137-140, 1998.

  1. How effective are tooth transplants? What factors govern the success of tooth transplants?

  1. ProyeMP, Polson AM. Repair in different zones of the periodontium after tooth reimplantation. J. Periodontol. 53:379-389, 1982.

  2. Pogrel MA. Evaluation of over 400 autogenous tooth transplants. J. Oral Maxillofac. Surg. 45:205-211, 1987

ORTHODONTICS

What effect do malposed teeth have on periodontal health?Can orthodontic therapy improve malposition? What affect does this have on the periodontium? What can patients expect during and after orthodontics?

Ainamo 1972                           NO ARTICLE             

P:Retrospective study looking at the relationship between malaligned teeth and periodontal disease in different groups of teeth.

M&M:The dentitions of 154 Army recruits (age 19-22) were examined clinically and radiographically. The occurrence and degree of displacement and rotation was recorded in 4,316 teeth. PI, GI, retentive calculus index, and CAL loss were recorded. The teeth were bilaterally pooled and grouped into maxillary and mandibular anterior teeth, premolars and molars.

R: Only 60% of subjects brushed 1 or more times /day, and brushing was limited to anterior teeth and facial surfaces. The maxillary laterals and mandibular second premolars were most commonly malaligned teeth. In the maxillary anterior areas, the mean scores for plaque, gingivitis, dental calculus and loss of attachment increased with increasing severity of malalignment. In mandibular anterior teetha similar association was found between malalignment and extensive plaque formation, gingivitis and loss of attachment but not with calculus accumulation. In the premolar area, the difference was less and it became non-existent in the molar regions.

BL: The incisors and canines showed the most favorable retentive calc index scores, and was the only area that showed a positive correlation between malalignment, gingivitis and CAL loss. The other areas showed no correlation.

Chung 2000                         NO ARTICLE

P: To investigate and compare the presence and proportional distribution of periodontal pathogens in the subgingival plaque of adult crowded versus non-crowded dental regions.

M+M:30 orthodontic patients (19M, 11F; 18-56 years old). Criteria for anterior crowding had to be at least 2mm crowding. Orthodontic records taken: lateral ceph, pano, and FMX; periodontal exam done. PI recorded. Subgingival plaque samples taken from crowded and non-crowded regions (Test and Control of same patient). Supragingival plaque removed with a curette, and subgingival plaque sampled with sterile paper points. 9 bacteria studied: Aggregatibacter actinomycetemcomitans (Aa), P. intermedia, E. Corrodens, C. rectus, Capnocytophaga species. Fusobacterium species, Peptstreptococcus micros. P. Gingivalis and B. forsythus determined using culture and immunoflorescence.

R: Supragingival plaque accummulation in crowded regions was SS greater than non-crowded. Crowded regions contained more species of periodontic pathogens than the samples from non-crowded regions. More spirochetes and motiles were present in the crowded region samples. Fusobacterium species, Capnocytophaga species, C. rectus and P. micros were more common in crowded regions. Amount of crowding was not linearly related to the number of pathogens. Patients with extremely good OH have less pathogens regardless of crowding.

BL:Subgingival plaque of crowded regions provide a more favorable environment for the colonization and growth of the periodontal pathogens.

Artun 1986           (root proximity)             ARTICLE

P: To assess the long-term effect of thin interdental alveolar bone on periodontal health after orthodontic treatment.

M&M: 25 adult patients, ages 28 to 55 years, with at least 16 years after orthodontic treatment were selected for exam based on the following criteria: 1) radiographic evidence with root proximity 2) models showing well-aligned teeth (ej. no open contacts), 3) closed interproximal contacts. Measurements were made on PA radiographs projected on a screen and clinical evaluation of predominantly anterior dentition. The position of the CEJ and the level of the alveolar bone (AB) were determined and the distance between CEJ-AB was measured. Also, the distance between the roots was measured. Root proximity was diagnosed when the roots were closer than 0.8mm.Adjacent or contralateral interproximal areas with more than 1mm between the roots were used as controls. Gingival health, level of attachment and bone in sites of thin interproximal bone were measured and compared with neighbouring control sites having normal bone width.

R:No SSD were observed in hygiene, tissue health or attachment and bone levels between areas with thin interproximal bone and controls with normal interproximal bone. However, when measured radiographically, the distance between CEJ-AB was significantly longer in the root proximity sites. This discrepancy was most likely due to radiographic distortion according to the authors. The study indicates that root proximity between anterior teeth after ortho treatment has no long-term detrimental effect on the periodontium as long as the teeth are well aligned.

D:Too few molar sites were included to draw conclusions for posterior teeth.

BL:In anterior areas, marginal periodontal breakdown is unrelated to the thickness of bone between the roots when the crown of the tooth is in the proper position.

Cr: Pas not standardized

Brown 1973                        ARTICLE

Purpose:To study the effects of a certain type of orthodontic tooth movement (uprighting molars) on existing periodontal osseous defects in humans.

Materials and methods: 5 patients were selected that 1) were Tx planned for extraction of all or many of remaining teeth and mandibular removable prosthesis, 2) advanced periodontal disease with vertical subcrestal osseous lesions and 3) loss of a mandibular posterior tooth, mesial inclination of the distal tooth and osseous defect associated with the mesial surface of that tooth. One patient served as control.

Standardized radiographs were taken at the beginning and the end of the experimental period, after metal endosseous reference points were inserted in order to evaluate the defects. Photographs were taken and casts from alginate impressions were also made. An assessment of the soft tissues was performed (evaluation of marginal gingiva, amount of attached gingiva, recession).

In the experimental group SRP was performed in the beginning of the experiment only and in the control patient it was repeated twice a week.

Orthodontic forces were applied to the test group that resulted in movement of the tooth in more distal and upright position. Following the completion of orthodontic procedures, the experimental teeth were stabilized for a minimum of 3 months to allow the remodeling of the bone. Patients were administered TTC until 14 days before the tooth extraction, which allowed complete clearance of the labeling medium from all tissues except the bone. Teeth in the experimental group were removed in block section and histologic analysis was performed.

Results:Patients had deep defects on the mesial of mandibular 2ndmolars. They exhibited substantial plaque deposition, gingival inflammation and proliferative changes in gingival architecture. Slight improvement was observed after SRP. As the orthodontic treatment progressed, gingival margin was positioned more apically and reduction in plaque retention, inflammation and edema was observed.

In all patients the molars were uprighted within a period of 90-120 days.

The experimental group showed 2.5 mm PD reduction more than the control patient. There was 0.63mm gain in bone height clinically and 1mm radiographically.

The histologic results would be subject of a forthcoming publication.

Conclusion:Orthodontic movement resulted in teeth with favorable axial inclination, significant reduction in the depth of the defects and desirable changes in the gingiva. Lesions would be more amenable to conventional periodontal techniques and complete pocket elimination could be achieved.

Kraal 1980                         ARTICLE

Purpose: To assess periodontal conditions in patients after molar uprighting.

Materials and methods:

  • 22 patients who had molar uprighting an average of 3 1/2 years prior were examined.

  • 15 patients received unilateral uprighting and 7 received bilateral uprighting.

  • Contralateral molars or adjacent molars served as controls.

  • Changes in bone levels, inflammation (gingival index) and probing depths were recorded.

Resutls:

  • Changes in alveolar height mesial to uprighted molars were not different from changes on the mesial of control teeth.

  • Gingival index scores around uprighted molars were not different from controls.

  • Pockets mesial to uprighted molars were shallower than mesial pockets in control (3.3 vs 3.9).

  • Gingival scores were worse around teeth with submarginal restorations regardless whether it was control or test.

BL: Because the periodontium adjacent to molars which were uprighted and retained with fixed partial prostheses was in no worse condition than that around equivalent teeth in a continuous dentition, it is concluded that molar uprighting is a reasonable mode of treatment.

  1. Can patients with periodontitis safely have orthodontics? What tooth movements can be offered for periodontally involved teeth? When can orthodontics be a detriment to periodontal health? How would this change how we treat or manage patients? If flap surgery is indicated, when should open flap debridement be utilized? Grafting? Osseous surgery?

Ong MA 1998                         NO ARTICLE

P: Review article on the interrelationship between periodontics and orthodontics in adults.

D: Ortho can be used to improve the perio condition via 1. Uprighting or repositioning teeth to improve parallelism of abutment teeth 2. Improving future pontic spaces, 3. Correcting cross-bites, 4. Extruding teeth (if fractured)/ Intruding teeth, 5. Correcting crowding of teeth, 6. Achieving adequate embrasure space and proper root position, 7. Repositioning teeth for placement of implants, 8. Restoring lost vertical dimension, 9. Increasing or decreasing overjet/ overbite, 10. Closure of diastemas

  • Ortho forces influence on bone (Reitan 1985, Proffit 1993a): resorption in areas of pressure and new bone formation where there is tension. When pressure is applied to a tooth, there is an initial period of movement for 6-8 days as the PDL is compressed. Compression of the PDL results in blood supply being cut off to an area of the PDL and this produces an avascular cell-free zone by a process termed “hyalinization”. When hyalinization occurs, the tooth stops moving. Light forces will cause only a short delay in txt, whereas heavier forces might cause a longer period of delayed movement. The PDL must be regenerated for movement to occur again. This regeneration cannot occur in areas of inflammation.

  • Lindhe (1989) recommends that in the initial stage of ortho txt in adults, an interrupted force of 20-30 g be used. Later on the force may be increased (up to 30-50 g in tipping and 50-80 g in bodily movements, corresponding to a distance of movement of 0.5-1.0 mm. per month) depending on the degree of marginal bone loss and the amount of remaining alveolar bone. Melsen (1989) published that intrusion can be done in perio healthy patients at a rate of 5-15g/tooth (lower force).

  • Multiple studies show that teeth can be moved into adjacent osseous defects, have extrusion and labial tipping of the anterior teeth without jeopardizing the perio support if there is adequate plaque control.

  • Ericsson has published multiple studies showing that ortho treatment in the presence of perio dz can worsen the perio condition, whereas even in reduced periodontium if the plaque control is adequate, teeth can be moved with no consequence to the perio apparatus.

  • With derotation, circumferential superficial fiberotomies can be done, even multiple times and decrease the possibility of relapse. This procedure should be done very close to the end of ortho txt. Another indication for CSF is forced eruption when the perio apparatus needs to remain at the same apico-coronal dimension as the tooth moves more coronally.

  • Ortho bands on periodontium: short-term: gingivitis and gingival hyperplasia NOT associated w/CALoss in children (Baer & Coccaro 1964, Zachrisson & Zachrisson 1972, Kloehn & Pfeifer 1974, Alexander 1991). There are differing opinions on adults, in that there is no long term effect (Sadowsky & BeGole 1981, Poison & Reed 1984, Poison et al. 1988); some effect – loss of attachment in adolescents (Alstad & Zachrisson 1979); – root resorption in adults (Trossello & Gianelly 1979)

  • Although a higher amt of periopathogenic bacteria can be seen after band placement, neither adults nor adolescents appear to be at a higher risk for developing perio dz.

  • Open and closed SRP and/or gingival augmentation should be performed as appropriate prior to any tooth movement (Glickman 1964, Prichard 1965, Proffit 1993d). Any pocket reduction surgery including osseous should be delayed until the end of txt b/c tooth movement itself might modify the gingival or osseous morphology. (Goldman and Cohen 1968). Close monitoring and shorter SPT intervals might be indicated.

  • Implants and ortho: successful cases have been reported using implants to: retract and realign teeth (Odman et al. 1988, Arbuckle et al. 1991, Block & Hoffman 1995), close edentulous spaces (Shapiro & Kokich 1988, Roberts et al. 1989, Roberts et al. 1994), correct midline and anterior tooth spacing (Odman et al. 1988), reestablish proper A-P and mediolateral positions for malposed molar abutments (Arbuckle et al. 1991, Haanaes et al. 1991), intrude and/ or extrude teeth (Odman et al. 1988, Haanaes et al. 1991, Salama & Salama 1993, Southard et al. 1995), correct a reverse occlusal relationship (Shapiro & Kokich 1988, Van Roekel 1989, Higuchi & Slack 1991), correct an anterior open bite (Roberts et al. 1984), protract a single arch or the entire dentition (Higuchi & Slack 1991) and provide stabilization for teeth with reduced bone support (Odman et al. 1988).

BL:Perio health is essential for any dental treatment. Adult patients must undergo OHI and perio maintenance during active ortho treatment. Close monitoring of adults with reduced perio support is mandatory. Adult orthodontic teeth movement can be performed on both healthy and diseased periodontiom with few detrimental effects (root resorption) if perio inflammation is controlled and meticulous OH maintained throughout active therapy.

Ericsson 1986                        ARTICLE

P: A review to report on studies performed in beagle dogs attempting to evaluate the effect of orthodontic and jiggling-type trauma on the supporting structures of premolars.

D:The reports have unanimously demonstrated that in situations where orthodontic or jiggling forces were inflicted on teeth with a normal periodontium, or on teeth with overt signs of gingivitis, the PDL tissue reacted by transitory signs of inflammation. These phenomena occurred without the concomitant loss of clinical attachment and development of pathologically deepened periodontal pockets. If jiggling trauma was inflicted on teeth with an ongoing plaque-associated destructive periodontitis, the resulting inflammatory reactions caused enhanced loss of attachment and angular bony defects. When orthodontic type of trauma is allowed to act on a single tooth or a group of teeth, separate pressure and tension zones within the PDL will develop and later alveolar bone and root cementum also involved. Orthodontic tilting movement of teeth (ie. Intrusion) in a plaque-infected dentition may shift a supra-gingival located plaque into a sub-gingival position resulting in periodontal tissue breakdown. Forces causes bodily movement will not affect the supra alveolar tissue and not cause AL even with the presence of supraG plaque.

Ericsson 1977                         ARTICLE

P:To study whether it is possible, by orthodontic movement, to shift a supragingival plaque into a subgingival plaque situation and to test the tissue reactions around tilted and intruded plaque-infected teeth.

M&M: 5 beagle dogs had mandibular 3rd PM’s extracted and had defects surgically created on lower 4th PM’s and copper bands placed with plaque accumulation for 21 days. Cotton ligatures were placed for 210 days. The dogs were fed a plaque inducing diet during this period. APF was then performed at day 210 (after perio breakdown had occur), a notch placed at the level of the alveolar bone and OH instructed for 60 days. Ortho appliances producing tipping and intrusion forces were placed. A spring with 40-50 grams of force was installed to tip the lower 4th PM mesial and apical. Plaque was allowed to accumulate on right side (test group), the other side (control group) received OH bid until day 450 when dogs were sacrificed. Standardized radiographs and CAL measurements at days 210 & 450, as well as histometry was performed.

R:Both test and control teeth were tilted and intruded, with NSSD. The size of the CT infiltrate and PDL area was SS greater for the test group. In 4 out of 5 dogs of the test group resulted in the apical shift displacement of CT attachment. Plaque-infected teeth showed subgingival plaque and pocket epithelium, a large supra- & sub-gingival infrabony cell infiltrate, and angular widening of the PDL. Control teeth showed no subgingival plaque and the epithelium had the appearance of a junctional epithelium. Clinical measurement, control group gain attachment and test group loss some attachment (+1.2mm vs. -0.5mm), but histologically in the attachment level no sig difference was found.

BL: Ortho intrusion may shift a supragingival plaque into a subgingival position. This movement in plaque-infected teeth may result in infrabony pocket formation.

Corrente 2003                         ARTICLE

P:To evaluate the effect of a combined approach (periodontal surgery and orthodontic intrusion) in treating adult periodontal patients with infraosseous defects in extruded maxillary central incisors

M&M:10 adult patients with advanced periodontal disease with extruded maxillary central incisor with infrabony defect at its mesial aspect and probing depth (PD) 6 mm were included. Patients were treated by SRP and then orthodontic intrusion. Maintenance therapy was performed every 2 to 3 months until the orthodontic treatment was completed. At baseline, PD and clinical attachment level (CAL) were measured. The vertical distance between the horizontal projection of the bone crest on the root surface (TD) and the most apical point of the bone defect, and the horizontal distance from the bone crest and TD were assessed on standardized radiographs.

R:Mean PD reduction was 4.35 mm, with a residual mean PD of 2.80 mm (Mean initial 7.15 mm). Mean CAL gain was 5.50 mm (Mean initial 8.95 mm, final 3.45 mm). The mean radiological vertical and horizontal bone fills were 1.35 mm (initial 4.3 mm, final 2.95 mm) and 1.40 mm (initial 3.4 mm, final 2 mm) respectively. All differences were of statistical significance (P<0.001).

B/L:The combined orthodontic and periodontic therapy resulted in the realignment of extruded teeth with infrabony defects, obtaining a significant probing depth reduction, clinical attachment gain, and radiological bone fill.

Polson 1984                          ARTICLE

P:To evaluate the effect of tooth movement on the osseous morphology and CTA level of intrabony defects.

M&M:4 rhesus monkeys, all but one incisor in each arch removed and allowed to heal for 6 months. Orthodontic bands were placed on the cuspids (anchoring teeth) and fitted with a rectangular arch wire. The arch wire was connected to the incisor via a bonded bracket. Intrabony pockets (mesial or distal) were created around the incisors by placing elastics around the necks of the teeth. After 5 months of active pocket formation, 7 to 8mm deep pockets could be probed (approximately 50% attachment loss) and radiographs demonstrated the presence of mesial and distal angular defects. The elastics were removed 2 months later, the teeth were root planed to the bottom of the angular defect. OH program (toothbrushing and topical application of 2% CHX 3 times/week) was maintained until the end of the study. 3 weeks after the initiation of OH program, the orthodontic appliance was activated to move the experimental tooth in either a mesial or distal direction into the osseous defect associated with the intrabony lesion. 4 incisors were moved into the defect and the other four incisors with induced intrabony pockets were left as controls (no tooth movement). 3 months after initiation of treatment the teeth had moved 6mm. Retained for 2 months and removed for histology.

R:Controls exhibited angular defect morphology with the epithelial lining extending apical to the level of instrumentation. The end of the epithelium was located 2 to 3 mm apical to crestal bone. Experimental group at pressure side exhibited narrowing of the defect with epithelial lining of the root surface to the apical extent of root instrumentation. The root exhibited some resorption apical to the area of instrumentation. New bone was present adjacent to the PDL space. No new CTA was demonstrated. Tension side: the angular defects were not present and the crest of the bone was apical to the level of root planing. There was no evidence of new CTA to the instrumented portion of the root. New bone and normal PDL were apparent.

CON:Histology is necessary to critically evaluate the remodeling process. Definitive changes in osseous morphology occur without any changes in CTA levels. Ortho may be carried out on compromised teeth without further CAL loss when plaque and inflammation are controlled.

Cardaropoli 2004                        ARTICLE

P:To evaluate the predictability of a combined orthodontic–periodontic treatment in determining

the reconstruction of the interdental papilla between maxillary central incisors.

M+M:28 healthy patients (22F, 6M) with infrabony defect on #8 or #9 w/ PD of at least 6mm; and extrusion of one maxillary central incisor were treated. All defects were treated w/ OFD (no graft or membrane placed)- FTF was reflected extending from the distal of both centrals w/ vertical releasing if needed- intrasulcular incisions only, no attempt for papilla preservation technique. At 7-10 days post-op, ortho movement was begun. Teeth were intruded, realigned, and diastemas closed via contiguous and light forces of 10-15g/tooth. Ortho therapy lasted 6-18 months, w/ a mean time of 11.7 months and pts had maintenance appts every 3-4 months during therapy. PD, CAL, and papilla presence index were assessed at baseline, at end of treatment, and at 1 year.

R:All parameters showed statistical improvement between the initial and final measurements, and showed no changes at follow up time.

The mean residual probing depth was 2.5 with a decrease of 4.3 mm, while the mean CAL gain was 5.93mm. The average distance from bone to contact point was 6.46mm (range 5-9mm).

The initial papilla presence index (used Nordland & Tarnow classification system) mean was 1.57 at baseline and 0.61 at the end of observation.

NSSD in reconstruction of papilla in thin vs thick biotypes.

BL: At the end of orthodontic treatment, a predictable reconstructions of the papilla was reported, both in pts with thin and thick biotypes.

Wennstrom 1993                         ARTICLE

P:To evaluate the effect of orthodontic tooth movement on the level of the connective tissue attachment in sites with infrabony pockets.

M&M:4 beagle dogs had 2nd and 4th premolars extracted. No plaque control measures at any point in the study. Angular bony defects were sx created at the mesial of 3rdpremolars with a notch placed at base of defect on the root. Cotton ligatures were placed for 3 weeks and an additional 2 months of plaque accumulation occurred before ortho movement began. In each dog, one premolar moved through the defect and one moved away from the defect. Maxillary teeth 3rd PM served as controls (no ortho movement). After 5-6 months of ortho movement, teeth were stabilized for 2 months before biopsy, then removal of appliances. Clinical assessment (PPD, CAL and tooth position) with radiographic and histological analysis was done.

R:Plaque accumulation and BOP present in both experimental and control group. Average sagittal movement 5 mm. The stationary control teeth gained some attachment levels at 5 months and had decreased PD, while the experimental teeth experienced some pocket depth increase and a loss of clinical attachment. However, the variance was high for both groups (1-1.5mm standard deviation). Histological evaluations for both groups showed presence of inflammatory cell infiltrate in the CT adjacent to the pocket epithelium extending apical to the crest of the alveolar bone. In the test group, all teeth had the apical level of the JE apical to the notch. This only occurred in 2/8 control teeth (most were at the notch) and the difference was SS.

BL:Orthodontic therapy involving bodily tooth movement with inflamed, infrabony pockets may enhance the rate of loss of the connective tissue attachment. Perio treatment should occur prior to initiating ortho treatment and oral hygiene should be maintained during treatment.

Araujo 2001                        ARTICLE

Purpose:To study if it is possible by orthodontic means to move a tooth in an alveolar ridge augmented with Bio-Oss and the tissue reactions associated with such a movement.

Materials and methods: 5 beagle dogs. After 1st, 2ndand 4th mandibular premolars were extracted in both sides, the interradicular septa of the 4th premolars were resected and the defect of the 4th premolar on the left side was filled with Bio-Oss. Flaps were then adjusted to achieve full coverage on both sides. 3 months later, orthodontic appliances were inserted. The force resulted in tooth displacement of 1mm/month on both test and control sides and treatment continued until the distal root of the 3rd premolar on the sides had been moved into the previous extraction sockets of the 4thpremolar. 2 weeks after the final activation dogs were sacrificed and histologic analysis was performed.

The following regions were identified:

  1. Zone A: bone tissue within the distal portion of the previous 4thpremolar site, 4x6mm

  2. Zone B: distal aspect of the distal root of the 3rdpremolar, pressure side and a 300wide area adjacent to it

  3. Zone C: the mesial aspect of the distal root of the 3rdpremolar, tension side

Results:All sites healed uneventfully. The mean movement of the 3rdpremolars was 3.85±0.57mm in the test group and 3.37±0.45 mm in the control group.

Zone A: In the test side it was comprised of a relatively dense mineralized bone, in continuity with the cortical bone of the alveolar ridge. This tissue contained lamellar bone, Bio-Oss particles and small amounts of immature bone and bone marrow. Some of the particles that were found above the alveolar ridge were encapsulated in connective tissue. In the control side, the marginal region of the extraction sites was occupied by a relatively thin layer of cortical, lamellar bone and cancellous bone apical to it.

Zone B: Same characteristics in both groups (arrested resorption, cellular cementum with fibers on the resorbed root surface, PDL with fibers organized in different directions and osteoclasts on the bony wall facing the PDL). On the test side Bio-Oss particles were found within the PDL, but not in contact with the root surface.

Zone C: Similar features in both groups. Newly formed woven bone and the trabeculae were perpendicular to the long axis of the tooth. Root surface was covered by layers of cellular cementum. No particles of Bio-Oss found.

In Zone A, the alveolar ridge of the test group consisted of 43.5% of mineralized bone, 14.8% Bio-Oss particles and 41% bone marrow. On the control group the ridge included 44.4% mineralized bone and 55.7% bone marrow.

In zone B, Bio-Oss occupied 8.9% of the space. Bone marrow was 23.7% in the test group and 38.8% in the control group.

The width of the PDL ranged between 0.28 – 0.38mm at the tension side (Zone C) in both groups.

Conclusion:Bio-Oss degradation and elimination occurs during orthodontic movement. The detailed mechanism is still not totally understood.

Melsen 1989                         ARTICLE

Purpose: to orthodontically intrude elongated teeth in adult pts with varying degrees of periodontal damage and evaluate the effects of treatment on the periodontal condition.

Materials and methods:

  • 30 adult pts, characterized by marginal bone loss & deep overbites, were treated by intrusion of the upper incisors.

  • Four different appliances for intrusion were placed:

    • a) J hooks & extraoral highpull headgear, b) utility arches, c) intrusion bent into a loop in a 0.17x 0.25inch wire, & d) base arch as described by Burstone.

  • Before treatment all patients received adequate periodontal treatment involving instruction, cleaning, and curettage. 15 pts had a MWF so pockets were <3 mm.

  • The intrusion was evaluated from the displacement of the apex, incision, and the center of resistance of the most prominent or elongated central incisor.

  • Change in the marginal bone level and the amount of root resorption were evaluated on standardized intraoral radiographs. The pockets were assessed by standardized probing and the clinical crown length was measured on study casts.

Results:

  • The results showed that the true intrusion of the center of resistance varied from 0 to 3.5mm and was most pronounced when intrusion was performed with a base arch.

  • The clinical crown length was generally reduced by 0.5 to 1.0 mm.

  • The marginal bone level approached the CEJ in all but six cases.

  • All cases demonstrated root resorption varying from 1 to 3 mm.

  • The total amount of alveolar support, that is the calculated area of the alveolar wall, was unaltered or increased in 19 of the 30 cases.

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