For infrabony defects, is flap curettage/open flap debridement an effective management option? What characteristics of the defect are associated with a positive healing response? What should be assessed prior to surgically treating teeth with vertical defects, especially if they extend to the apex?
After a flap is reflected and cleaned, what are the possible healing outcomes? What is necessary to analyze healing? What is the difference between reattachment, new attachment and regeneration?
Why would root submergence be an effective method of obtaining periodontal regeneration? What principles does this take into account? If a root is submerged, how does this affect healing? Why would this change or affect healing when compared to a replaced flap?
How does adding a bone graft to an infrabony defect compare to debridement alone? What results are needed to evaluate the healing?
Does placing a graft material into an infrabony defect automatically allow for regeneration?
Why or why not? What is the ideal particle size of a graft material? Why is this important?
What are the general principles of regeneration? Is this a predictable procedure? What surgical characteristics or techniques can increase the predictability of surgical success?
What are the characteristics of defects that allow for more predictable regeneration?
What patient characteristics can influence the outcome of periodontal regeneration? Which can we help control? What would a recommended recall interval be for patients having bone grafting?
For infrabony defects, is flap curettage/open flap debridement an effective management option? What characteristics of the defect are associated with a positive healing response? What should be assessed prior to surgically treating teeth with vertical defects, especially if they extend to the apex?
P: to discuss diagnosis and treatment of vertical bony defects
D: Vertical bony defects are caused by both periodontal and pulpal infection. X-rays do not always help to differentiate the process. The Tx objective is regeneration.
Periodontal Pulpal Quandary. (Combined periodontal pulpal disease)
- Difficult to Dx.
- Pulpal lesion becomes marginal periodontitis (Periodontitis) when it forms a sinus tract trough gingival crevice. Root resection is an alternative form of tx.
Dx of Pulpal Disease. (By signs, symptoms, pulp test, dental Hx, X-rays).
Periodontitis always starts at the margin of periodontium and progresses in an apical direction.
Bone resorption from pulpal disease heals by regeneration and resorption from p-itis heals by
repair.
Dx of intrabony periodontal defects. (X-ray, PD). Pockets are wide, sinus tracts are narrow, 3
wall defects occur where the bony arch is wide and cortical plates are thick. Tx of
intrabony perio-defect leaving the orifice of defect open to prevent formation of a long junctional
epithelium.
BL: Perio-Pulpal lesion are difficult to diagnose. Pulpal lesions have better prognosis than periodontal lesions.
Purpose: To quantitate the changes which occur throughout the entire circumferential extent of infrabony defects in pts with optimal plaque control.
M&M: 9 pts (38-61 years of age) with 15 defects. The mobility of each tooth was recorded. Mucoperiosteal flaps were raised and osseous defects were debrided. The dimensions of the defect were measured at mid-buccal, mid-lingual, the line angles, and the buccal and lingual aspects of the contact. The depth of each defect was recorded. Flaps were replaced at their original location. Pts were recalled once per week for the next 3-6 weeks in order to check plaque control, OHI, and routine prophylaxis. At 2, 4, and 6 months post-operatively, plaque indices were scored along with mobility and prophylaxis. 6 to 8 months after surgery all cases were radiographed, reentered, and osseous defects were remeasured.
Results:
Mean defect depth: 3.5 mm (range: 2-8mm).
Bone regeneration: 2.5mm (range: 1-5mm)
Crestal alveolar bone resorption occurred at almost ½ the location points and averaged 0.7mm
11 of 15 defects resolved completely. Shallow defects remained in the other 4.
Most teeth decreased in mobility by one degree.
Owing to the circumferential nature of most of these defects and their morphology, it was difficult to categorize each defect with regard to a specific number of osseous walls present.
BL: The behavior of an osseous defect (throughout its circumferential extent after surgical debridement and establishment of optimal plaque control) was characterized by a combination of 77% bone regeneration and 18% marginal bone resorption. 11 of the 15 had complete defect resolution
P: To determine what factors influence the healing response following treatment of intra-osseous lesions.
M&M: 84 defects in 51 pts in all areas of mouth examined. PD, CAL, and probing bone levels recorded preop and 6 months later with electronic probe. Full thickness replaced flaps, SRP, 3 min citric acid root conditioning followed by measurement of osseous defect circumference, # of tooth surfaces involved, and # of osseous walls (one wall if proximal only, two wall if B or L also, three wall if proximal, B and L). Osseous depth was recorded to acrylic stent. No defects recorded next to furcations. No osseous recontouring. Prophy q 6 weeks
R: There was a wide range of defect depth and morphology. The defects were measured for depth of 1-3 wall components. Mean PD was 7 mm with a range from 4.5-11 mm. PD decreased from 7 mm to 4.4 mm. Mean gain AL was 1.4 mm and mean gain of probing bone level was 1mm. The change of CAL was SS correlated to pre-operative PD and to the depth of the osseous defect. The best responding defects and worse responding defects had NSSD in defect characteristics, location of defect or age of patient.
D: # of walls, defect circumference, # of tooth surfaces involved, age, and location of defects showed little relationship to bone fill.
BL: CAL gain was sig correlated to pre-operative PD and to the depth of the osseous defect.
Purpose: To report changes that occurred after flap debridement of intrabony defects
M&M: 13 patients (14 sites) included in this study. PI and GI taken at each appointment; OHI and SRP before surgery, no instrumentation of teeth with suspected defects in phase one.
Surgery
Photographs and non-standardized radiographs were taken. Defects received debridement of granulation tissue, calculus removal, and were root planed. The defect was measured from the CEJ to the bone crest and bottom of the defect at 3 points: at the line angles and deepest point interproximally (or buccal/lingual). Intramarrow penetrations were not performed. Alginate and silicone impressions were taken during sx. The sites were sutured with the margins of the flaps open adjacent to the defects. Pts received maintenance every 3-4 months until re-entry (9-16 months).
Measurements (at the first surgery and re-entry)
- Bone scores from radiographs using Bjorn’s technique
- Direct measurement during surgery
- Model measurement (taken at same time point as clinical measurements)
- Volumetric analysis of defects using gunpowder
R:
One intrabony defect was narrow (1-2mm), 6 were medium (3-4mm), and 7 were more than 4mm wide. Seven of the 14 had a 50% or greater decrease in defect fill, while the other 7 had less than a 50% change. The bone score changed from 16.15 initially to 13.61 at re-entry. Attachment level was 7.48 mm initial and resulted in 4.72 mm at re-entry (2.76mm ALgain). The initial mean recession was 0.78mm, while at reentry it was 1.62mm.
The mean amount of repair from study casts was 2.56mm, while from direct measurements was 3.26mm. Further measurements were as follow:
- Measurements from model: mean crestal resorption was 9.7% and net defect fill 61%
- Direct measurements: mean crestal resorption was 7.7% and net defect fill 63.9%
- Volumetric analysis: 47.5% defect fill (estimated 10% error)
BL: Intrabony defects can repair significantly with OFD.
Cr: The probing attachment levels were taken at points which were un-instrumented prior to surgery. This could affect how deep the probe penetrated. No stent used to measure from CEJ-bottom of defect. Measurement error was not determined prior to the beginning of the study. An exact comparison cannot be made between the defect measurements taken during sx and those taken on the study models. Verification of the exact location of measurement points between the s measurements and those taken on the models was “not practical.”
P: To examine the relationship between pre-treatment characteristics (bone loss, tooth-bone angle (TBA), interradicular width (IRW)) of angular defects and changes in bone height relative to post-surgical duration.
M&M: Retrospective study. 53 proximal infrabony defects were included. The sites were located between mandibular molars and between 1st molar and 2nd premolar. They had been treated with flap curettage and periodic maintenance. Mean post-surgical period was 11.4 years. Pre-sx and final radiographs were enlarged and measurements were performed. Bone loss was calculated as a % of root length. Gain or loss of bone was recorded when that change was >2 SD from the measurement error. The sites were classified as 1-wall defects at the time of the surgery, although some defects had small 1-2 wall or 2-3 wall components in their most apical extent. Each angular defect consisted of a shallow and deep side. IRW was measured at the apical and coronal extent of the defect. Tooth-bone angle was measured. Sites were divided into 2 groups according to post-sx duration: years and 10 years. Pre-sx bone loss was divided into >50% and <50%. Statistical analysis was performed.
R:
Deep side (A): Sites which gained bone had a mean pre-treatment bone loss of 57.1%. The tendency for bone gain increased with extent of pre-tx bone loss. No correlation between bone loss following therapy and amount of pre-tx bone loss. Pre-tx TBA of deep-side sites which gained bone was more acute than the TBA of sites which lost bone. Sites that gained bone had a mean pre-treatment TBA of 31. As the TBA decreases the amount of bone repair increases. Deep-side sites which gained bone had a significantly greater mean IRW than sites which lost bone (3.1 vs 2.9). More gaining sites were found in the >10 year group. Bone gain was found predominately in sites with >50% bone loss.
Shallow side (B): No correlation was found between pre-tx bone height and the amount of gain or loss in bone height following tx. No correlation between shallow-side pre-tx TBA and the amount of gain or loss in bone height following treatment, or the depth of the defect. IRW was not related to an increase or decrease in shallow-side bone height following therapy.
DISC: The repair potential of the angular defect may be enhanced by the close proximity of vascular and connective tissue elements of the bone defect and the PDL. Other factors involved in bone growth; timing of the treatment relative to the disease activity of the lesion, anatomic factors, healing of the angular defects is partly a physiological tendency of the host to return alveolar bone to less angular state, quantity of cancellous bone (absence of cancellous bone at the alveolar crest has been associated with restricted osseous regeneration).
CON: The majority of the deep-side sites that gained bone had significant pre-tx bone loss, a small TBA and were at proximal spaces with intermediate width. At shallow -side sites, no correlation was found between pre-tx bone loss, pre-tx TBA and IRW with amount of gain or loss in bone height following therapy.
Lang 2000 ARTICLE
P: Review of conservative therapy for intrabony defects.
D:
One month following non-sx therapy including patient motivation, OHI and SRP lead to mean PD declining by approximately 1 mm in pockets originally displaying a PD of 4–6 mm and 2 mm in pockets with PD of 7–12 mm.
The treatment of intrabony defects using conservative approaches including access flaps without osseous is expected to produce an average gain of probing attachment close to 2mm. The defects can be expected to have bone fill (with new bone) up to 1.5mm without any placement of bone graft. This does not necessarily mean new attachment to the root surface.
The defect size has a profound effect on the treatment outcome for both probing attachment loss and gain as well as bone-fill values. Also, the angle between root surface and bony wall of an intraosseous defect represents another important factor in the healing process.
At angles greater than 45 degrees bone-fill is expected, whereas larger angles typically show no change or bone loss. Defects on root surfaces without furcations tend to have better chances of healing than those associated with furcations.
Post-surgical supportive care is one of the most important determining factors for positive treatment outcomes. However, for a given intrabony defect, the predictibility of the treatment outcome remains unknown.
After a flap is reflected and cleaned, what are the possible healing outcomes? What is necessary to analyze healing? What is the difference between reattachment, new attachment and regeneration?
Osseous repair of an intrabony pocket without new attachment of connective tissue
Purpose: to report a case in which there was osseous repair of an experimentally induced periodontal pocket without new attachment of CT fibers to the root surface.
Materials and methods
Periodontal Pocket produced on the mandibular right 1st molar of and adult Rhesus monkey. Orthodontic elastics were in place on this tooth for 6 months.
Full thickness flap was reflected and all soft tissue was curetted from the root surface and the alveolar defects. Roots were lightly planed, irrigated and sutured.
Results
The interproximal area between the mandibular 1st molar and 2nd bicuspid was the location of the pocket.
One year after treatment the pocket depth was reduced from 6mm to 2mm
Xrays and histological sections demonstrated healing of the infrabony pocket.
BL: Osseous repair may occur in an intrabony defect w/o new attachment between bone and root surface. Histology is the only accurate means of judging whether or not new attachment has occurred.
Purpose: To examine if the establishment of a new fibrous attachment is accompanied by regeneration of surgically removed buccal alveolar bone.
Materials and methods: Two beagle dogs were used. 8 weeks prior to the experiment teeth were scaled and polished every 14 days and cleaned with a toothbrush three times a week, in order periodontal tissues to be healthy.
At Day 0 the coronal 5-7mm of the buccal alveolar bone were removed from one maxillary and one mandibular molar, after a U-shaped incision. A notch was created in the root surfaces at the level of the surgically established bone crest.
Flap was sutured and slight pressure was applied so good adaptation is achieved. 0.2% chlorhexidine was used for plaque control from the day of the surgery till the day animals were sacrificed 8 months later. In each dog contra-lateral teeth served as controls.
5 sections of 5μm were used for microscopic analysis. The following linear distances were assessed: 1) CEJ to the most apical end of junctional epithelium (JE), 2)CEJ to the marginal level of the alveolar bone crest (BC) 3)CEJ to apical border of the prepared notch. CEJ-JE and CEJ-BC were also measured in the control teeth.
Results: In 2 (total of 8) roots apical cells of JE epithelium were located in the CEJ, the remaining six 0.5-2.5mm apically to CEJ.
In two specimens there was bone regeneration of 0.5mm, while in the remaining six specimens bone regenaration varied between 1.3 and 3.7mm.
Supraalveolar CT attachment was 1.2-4.2mm but there was no relationship between this and the amount of bone regeneration.
New cementum was always formed between apical portion of JE and the notch.
In areas with longer CT attachment the fibers were almost parallel to the root. The number of CT fibers which in these areas were inserted in the supraalveolar root cementum appeared to be considerably smaller than in the control teeth. In the test areas though that bone had regenerated close to its original height these fibers were similar to control teeth.
In all sections of control teeth the apical cell of JE were located at the CEJ and the JE-BC was 0.6-1.4mm. Most supraalveolar CT fibers were orientated perpendicular to the root.
The variations to bone regeneration dimensions may be because the mesio-distal dimensions of all defects created were not identical, and the adaptation of the flaps also varied.
BL: Coronal displacement of the CT attachment level obtained after reattachment procedures is not necessarily followed by coronal regrowth of the alveolar bone. (We cannot define if healing is reattachment or new attachment.)
P: To describe histological repair of infrabony lesions following open flap debridement of infraosseous lesions.
M&M: case report of 4 pts w/ infraosseous lesions around periodontal hopeless teeth which were treated w/ OFD; given 1 week antibiotics and recalled q 4 weeks for cleanings until block resections were removed @ 4-6 months post-op and examined histologically. Radiographs, Navy Plaque Index, and measurements of defect using a stent were taken at baseline and at time of removal of block sections.
R: Histological sections frequently showed a flattened alveolar crest denoting post surgical crestal resorption, and closure by soft tissue adhesion in the form of a long junctional epithelium (JE). There was limited parallel-oriented collagen fiber adhesion. Neither osteogenesis nor cementogenesis were observed.
B.L OFD usually results in soft tissue adhesion of crevicular or long JE as its primary healing response, not new attachment.
P: To determine if alveolar bone located adjacent to a root surface which has been deprived of its periodontal ligament and cementum layer can stimulate a new CNT attachment.
M&M: 3 Macaca monkeys. Established good oral hygiene. All max/mand incisors were extracted. The incisors on the left had root planing along buccal surface ~1/2 root length then notched at apical extent of instrumentation and reimplanted. Incisors on the right had no therapy and were reimplanted as well. In two monkeys, the buccal alveolar bone was removed to a level ~1/2 the depth of the socket. All teeth were reimplanted within 4 minutes of extraction and splinted. At 6 months post-op the animals were sacrificed and block sections were evaluated histologically.
R: Irrespective of the presence or absence of alveolar bone, a fibrous reattachment failed to form on that part of the re-implanted teeth which had been deprived of their PDL. The JE was seen to extend apically as far as the root planing (to the notch). CNT attachment formed on roots with an intact PDL (on teeth without root planing), but no new bone formed in areas where it was removed. Where the bone was not removed but the teeth were root planed, JE was found. Bone adjacent to a planed root surface does not favor the formation of a new attachment.
BL: The presence of bone tissue may have little influence on formation of a new CNT attachment, and intact PDL fibers appear necessary for new CNT attachment. Rt Pl of even undiseased roots prevented new CTA
Purpose: To investigate if new attachment will form on previously periodontitis-involved roots when reduced but healthy PDL tissue persists after periodontal treatment, and when epithelial migration is prevented.
M&M: Periodontal disease was induced with orthodontic elastics around maxillary and mandibular second premolars or first molars of 4 monkeys until 50% of the supporting tissues were lost. Neighboring tooth was resected and kept to maintain the height of the jaw bone. 3 months following ligature removal, the crowns and roots were resected, pocket epithelium and granulation tissue excised, cementum removed with a diamond bur, and roots were then covered with a mucosal flap. All animals were sacrificed after 3 months of healing and serial sections cut in the mesio-distal direction were histologically examined.
Results: New CT attachment and cementum formed on the previously periodontally-involved roots, but it was restricted to the apical part of the instrumented root portion, while the root area coronal to this was characterized by resorption. Out of the 16 roots, 6 roots penetrated the covering soft tissue flap within the first week after the surgical procedure. In roots which remained covered for the entire 3 months (10/16), this coronal extension of fibrous attachment averaged 1mm (0.1-2.6 mm range). Re-growth of supporting bone had occurred in the bottom of 2 angular defects (1.5mm and 2mm). In the exposed roots (6/10) the extent of the newly formed attachment was between 0-0.8mm (average 0.2 mm). The coronal extension of the newly formed cementum coincided with the apical termination of the epithelium on all root surfaces, and no bone formation was observed adjacent to the exposed roots.
BL: New attachment can form in monkeys on periodontitis-diseased roots denuded of cementum when themed by coronal migration of cells originating from the PDL (supports the concept of the PDL as origin of new attachment progenitor cells).
Purpose: To compare periodontal repair and amount of new attachment after surgical treatment procedures involving hand instruments, ultrasonic devices or chemical cleaning and citric acid conditioning of periodontally-involved root surfaces.
M&M: Experimental periodontitis was produced in 4 monkeys by use of elastic orthodontic ligatures. Ligatures were changed every week. After 6 mo the teeth showed severe furcation involvement. Removed ligatures for 1 month at which time each quadrant was subjected to different periodontal treatment (no surgery+OH , surgery+hand instruments, Surgery+ultrasonics, flap+chemical cleansing (cetylpyrimidinium chloride and sodium-N-lauroyl sarcosine for 30 min each), or flap+chemical cleansing+citric acid. Monkeys were given TTC injection on the day of the surgery, at 7, 14 and 21 days post-op and sacrificed at 9 months, and prepared for histomorphometric analysis.
Results: Formation of new cementum and new bone was determined by means of tetracycline labeling. RP with an ultrasonic device or with HI almost completely removed the cementum and a portion of the peripheral dentin. The root surface was more uneven after treatment with the ultrasonic device than after using HI. No new attachment could be found after RP. Cleaning of the periodontally involved root surfaces with the two detergents without RP resulted in a significant amount of new attachment (1.3-1.5mm).
Discussion: In relation to SC/RP during Sx, this study found similar results as Caton et al 1980 with regards to lack of new attachment. As with Badersten's study (1984), this study found no difference in repair when HI or US are used.
Why would root submergence be an effective method of obtaining periodontal regeneration? What principles does this take into account? If a root is submerged, how does this affect healing? Why would this change or affect healing when compared to a replaced flap?
P: To evaluate the possibility of obtaining complete reattachment with formation of cementum, bone, and PDL in cases where the root cementum had been devoid of the periodontal tissues for a long time and where the epithelium was excluded from the healing process.
M&M: There were 11 teeth included in the study, in a total of 7 people. All teeth were vital, with increased mobility, extensive pockets, and extraction was recommended. Root canals were performed on these teeth, and after 3 to 6 weeks: crown cut off at gingival margin, entrance to canal sealed with amalgam, root surface scaled and planed, granulation tissue on pocket walls was removed. FTF with vertical incision was performed and displaced over the cut tooth. There were 4 controls and standardized x-rays were utilized to determine bone fill (at least 1mm change required for it to be taken into consideration).
R: All but 2 teeth were exposed 2-6 months after Sx. Pocket formation after exposure was not an issue (no pockets greater than 3mm). Some bone regeneration could be seen in x-rays in most cases. Marginal bone resorption could not be seen in any case (re-entry clinically). Histology was performed after 6 months only on 3 teeth, 1 of which became exposed after 5 months. There was healing by means of cementum, PDL and bone, although there were some signs of resorption (potentially due to infection from the root canal or because the tooth was totally luxated during the scaling), especially in the apical regions. Most of the fibers were parallel to the root surface. In marginal areas, there were some oblique fibers inserting into new cementum and bone.
BL: Teeth can be maintained submerged and periodontal regeneration may occur when the epithelium is excluded, although root resorption is also possible.
P: To determine whether retained roots maintain vitality in monkeys after the crowns are removed and the wound is sealed with a mucoperiosteal flap.
M&M: 2 monkeys provided 12 test sites each equally divided between maxilla and mandible. Experimental sites included 3rd & 4th premolars, central and lateral incisors in each jaw. The surgical schedule was designed to produce specimens at intervals of 2, 4, 6, 8, 10 and 12 months. The absence of pre-op dz was verified by periapical radiographs and photographs. FTFs were raised and crowns in test sites were cut off 3 mm subcrestally. Flaps were sutured to cover the resected site. A tooth adjacent to experimental site served as control. Animals sacrificed at 2 months after the last operation and histological evaluation was done.
R: Healing had no complications except shortening of mucobuccal fold. Histologically, no SSD between experimental & control sections regarding pulpal tissue. Osteodentin was overlying the area over the amputated pulp. Osteocementum was formed to a variable extent over the root surface. In all sections there was closure of the root canal at the amputation site. Cellularity within the pulp was increased & pulp did not show loss of vitality. No periapical pathologic change was observed. Root resorption and epithelial proliferation were observed in 2/24 experimental teeth.
BL: Retention of vital roots in the alveolus after primary closure with a flap is possible in monkeys. Progressive closure of the amputated pulp occurs via osteodentin deposition. Root resorption and epithelium proliferation observed in 2/24 (8%) of experimental teeth.
P: To study the regeneration potential of perio tissues in infrabony defects around vital submerged roots.
M+M: Seven patients (25-55 yrs old) with advanced periodontitis and systemically healthy. Maxillary anterior teeth with periodontal infrabony defects of two or more bony walls w/ mobility no greater than class II, planned for extraction were used for the study. FTF reflected. A total of 20 teeth had their crowns amputated at the level of the alveolar crest, granulation tissue was removed and root surfaces SRP. 12 of the roots were submerged (experimental group) and in 6 roots, the flap was replaced to its original position (control group). PD and standardized radiographs taken pre-op as well as defect depth, and histo to determine bone formation at 6 and 9 weeks, and at 3, 5, 6, 7, and 8 months.
R:
CT fibers filled the osseous defects and were oriented parallel to the root surfaces in the majority of the cases. New cementum was observed lining the root surface at the base of 2 successfully submerged defects but there was no apparent move coronally on any specimens.
8/9 submerged defects exhibited positive radiographic changes, and the 6 control teeth showed no positive radiographic changes.
All successfully submerged roots showed histologic evidence of new bone formation. Not apparent in any of the controls.
Either no epithelium or only a narrow band was found adjacent to successfully submerged roots;
The defects of all control teeth and non-submerged experimental teeth showed epithelial down-growth and chronic CT infiltrate
Pulpal tissue of the submerged roots appeared vital without significant degeneration on inflammatory changes and was continuous with the overlying CT.
BL: The results of this study shows evidence to the possibility of maintaining alveolar ridge height following the submergence of vital root segments with their associated osseous defects. Submerging of vital roots resulted in bone fill of associated periodontal vertical defects, but the CT was not functionally oriented to the root surface, nor was there significant cementogenesis.
Histologic evaluation of new attachment apparatus formation in humans part I
Purpose: to evaluate the formation on new attachment apparatus following flap curettage in intrabony defects and root planning of pathologically exposed root surfaces.
Materials and methods
13 volunteers who had 2 or more maxillary or mandibular premolars, cuspids, or incisors recommended for extraction (periodontal disease)
Teeth were randomly selected to undergo vital root submersion (coronectomy), a mucoperiosteal flap was reflected on the facial surface and a gingivoplasty was performed on the lingual or palatal surface.
A small hole was place on each crown and suture material was passed through the hole to safeguard against aspiration.
Crowns were amputated at the highest level of the alveolar crest.
A round bur was used to notch the root at the base of the calculus in order to delineate exposed from not exposed tooth surface.
SRP performed, bony defects were classified and measured from notch to depth of defect.
The bony walls of the defects were penetrated with ¼ round bur (intramarrow penetration) to enhance rapid proliferation of blood vessels
All patients were given Tetracycline 250 mg 4 times a day for 14 days.
At 6 months submerged and non-submerged roots were removed in a bloc for histology.
Results and Conclusions
In submerged intrabony defects treated by flap curettage and root planning.
Is possible to form new attachment apparatus on previously exposed roots
More new attachment apparatus will form in submerged roots and the amount of new attachment apparatus formed is limited by the amount of new bone and Cementum formation.
New attachment was formed more frequently in submerged defects
New Cementum formed over old Cementum and dentin.
PDL was oriented parallel, perpendicular.
Extensive root resorption, ankylosis, and pulp death are not common
In nonsubmerged intrabony defects
New attachment was not observed on previously exposed root surfaces.
Small amount of Cementum, CT or bone formed previously.
Root resorption, ankylosis, and pulp death are not common.
How does adding a bone graft to an infrabony defect compare to debridement alone? What results are needed to evaluate the healing?
Purpose: To describe a technique to submerge vital roots of periodontally involved teeth with intrabony defects.
Technique: Gingivoplasty is performed in keratinized tissue on the palatal (lingual) surface of the roots to be submerged. It should extend 2-3mm over bone. Sulcular incision is made on the buccal side, in order all keratinized tissue to be maintained. Vertical incisions are made at the proximal line angles of adjacent teeth. When edentulous areas are adjacent to the tooth to be submerged vertical incisions are made at least 5mm from the tooth. Crowns are severed at the highest level of the alveolar crest, vitality is confirmed by observing bleeding from the pulp canals. Intrabony defects are completely debrided, SRP is performed and root grooves and concavities are eliminated whenever possible. Releasing incision of the facial flap is then performed till it completely covers the gingivoplasty. Ultrasonics is then used to debride the area, bone is perforated and PDL is enlarged with a curette.
Bone graft of high osteinductive potential is then placed around the defect to cover all exposed root surfaces. Flap is placed over the gingivoplasty and sutured.
It is preferable to delay insertion of the prosthesis for at least one week, and religned with a soft denture material in 3-4 weeks. Patient is then placed on a soft diet for 1 week and a broad-spectrum antibiotic is prescribed for 10 days. Sutures can be removed in 7 to 10 days. Patient is seen on a weekly basis for the first month, healing is usually complete by 3 months.
Discussion: 150 vital roots were submerged using this technique. All of them have been removed and biopsied at 6 months. 10% of the roots failed to remain submerged, mostly in the mandible and in sites with less KG.
No clinical or histologic evidence of root resorption, ankylosis or periapical pathology in any case.
In 4-6 months after coronally advanced flap, the vestibular depth was restored near its original position.
A case report is presented in which mesial of #23 there was an 8mm one wall intrabony defect, almost to the apex of the tooth, with calculus extending up to 4mm from the base of it. After surgical re-entry new cementum was observed, new PDL fibers, new bone formation coronal to the level where the apical end of calculus used to be.
BL: Histologic results indicate that repair of submerged grafted defect is predictable. Many hopeless teeth can be used for preservation of alveolar ridges, or uncovered to serve as abutments for prosthesis.
P: To document healing of intrabony lesions treated with curettage and root planing, versus osseous autografts and allografts with and without root planing.
M&M: A total of 25 teeth (premolars or anterior teeth) from 21 pts were used. Teeth included were associated with an intraosseous defect and needed extraction. However, only 15 blocks (in 14 pt) could be used. The defects were classified by number of walls, x-rays were taken with a probe in the defect, and the mobility was assessed. After a flap was elevated and debridement was performed, a notch was made at the bottom of the defect. The defects were treated with autografts (same area or tuberosity), allografts (fresh frozen iliac crest), or no graft (SRP). Some grafted sites were planed, while others were simply debrided. At 6 mo or 1 yr the block was taken and histology performed. No OH was given to pt and pts were not seen for recall for 6 months, and therefore, plaque deposits were present in most cases.
R: JE proliferated below the alveolar crest in all groups. From gingival margin to the bottom of the original osseous defect, the pocket was 21-48% and JE 35-47% of it. The JE measured from 1-4.5mm (mean 2.8mm), and the osseous defect accounted for 51-67% of the total depth. The JE frequently was apical to grafted bone. The penetration of epithelium into grafted bone was more pronounced at sites that had not been planed (19%, 39%) than at sites that had been planed (4%, 7%). Grafted sites had more obvious deposits of new cementum, especially when root planed. No bone fill present at non-grafted sites, while there was 17-61% bone fill at grafted sites (measured by most coronal bone chip continuous with new bone). There were often non-vital bone chips located coronally that were surrounded by epithelium at grafted sites.
BL: With generally poor OH, JE will proliferate apically toward the defect, in all cases. There was no bone fill at sites that only received curettage and root planing.
Does placing a graft material into an infrabony defect automatically allow for regeneration?
Why or why not? What is the ideal particle size of a graft material? Why is this important?
P:
1) to develop an animal model for clinical and microscopic study of the treatment of 3-wall defects
2) to compare the effect of new attachment procedures
3) to study microscopically the healing pattern and mode of regeneration with and without the various graft materials.
M&M:
Part 1
8 Rhesus monkeys, 93 three-wall defects produced after mucoperiosteal flaps with 3mm mesiodistal width. A notch was made in the root surface at the bottom of each defect and the depth of the intrabony lesion was determined by the distance from the notch to the margin of the bone. The defects were filled with periodontal dressing or a steel band to prevent spontaneous healing. The monkeys were sacrificed after 1 to 24 weeks. The jaws were dissected and specimens were used for microscopic analysis.
R: clinically: plaque deposits, inflamed gingiva, pocket formation to areas subjected to surgery, 1-2mm recession during the postsurgical period. Microscopically: 49 out of 75 defects processed for microscopy displayed signs of chronic inflammation in the connective tissue and apical migration of the pocket epithelium. After 4 weeks all intrabony lesions were entirely epithelialized. The base of the pocket epithelium coincided with the notch in the root surface. In a few specimens new attachment had occurred in a small area adjacent to the notch. In most long-term specimens the width of the defects had decreased.
Part 2
12 adult Rhesus monkeys, 94 intrabony defects were produced, 8-10 weeks later monkeys were anesthetized, mucoperiosteal flaps reflected, all soft tissue from intrabony defects was removed, root surfaces were planned, notches were produced at the bottom of the defect. 27 defects were grafted with autogenous cancellous bone, 24 defects with fresh autogenous hip bone marrow, 23 defects with frozen autogenous hip bone marrow and 20 defects were not grafted.
R: 73 of the 94 treated defects were evaluated.
Regeneration 75-100% 50-75% 0-50%
Cancellous bone 66.7% 23.8% 9.5%
Fresh bone marrow 88.2% 11.8%
Frozen bone marrow 84.2% 15.8%
No transplant 56.3% 25% 18.7%
New attachment (new cementum and PDL formation)
Cancellous bone 48.5%
Fresh bone marrow 6.5%
Frozen bone marrow 68%
No transplant 56.3%
Healing Pattern:
1 week after: blood clot partly organized, a fibrin network was seen in some portions, osteogenic activity was seen on the bony walls of the defects, resorption of alveolar crest, bone formation adjacent to the grafts, no sign of cementum formation, epithelium extended to the notch (level of alveolar crest).
2 and 3 weeks: pronounced osteogenic activity, most osteocytes had survived transplantation of the fresh marrow transplants, while in the cancellous bone and the frozen hip bone marrow most cells appeared non-viable. Proliferation of epithelial cells along the root surface and no apparent cementum formation until third week.
6 to 24 weeks: newly formed cementum increased in thickness. After 24 weeks only a few areas showed well defined fiber bundles attached to the new cementum. Between the epithelium and the notch area in the bottom of these defects, connective tissue was in contact with the root surface apparently without fiber attachment. Healing by ankylosis was seen in intrabony defects treated with fresh hip bone marrow and was accompanied with resorption.
BL: This study has shown:
1) three- wall intrabony defects showing complete epithelization may be produced in the monkey in four weeks.
2) new attachment is three-wall defects is obtained with equal success with and without autogenous bone grafts.
3) intrabony lesions receiving fresh bone marrow transplants heal by ankylosis and root resorption whereas the healing of autogenous frozen hip marrow and cancellous bone grafts is associated with new cementum formation and establishment of new PDL. The degree of infection and the rate of apical migration of the gingival epithelium seem to be essential factors in preventing new connective tissue attachment.
Caton, Nyman, Zander 1980 ARTICLE
Purpose: To determine the effect of four regenerative procedures on the connective tissue attachment level in Rhesus monkeys
M&M: Eight male monkeys. Pockets produced by Caton & Kowalski method, all teeth scaled 3 months. after pocket production. Brushing, flossing with disclosing solution, and 3 min topical application of 2% CHX 3 times a week. After 3 weeks they were randomly assigned to four groups and received treatment on one side while the contralateral side was used as control. Procedures were: (1) MWF without osseous surgery. (2) MWF with frozen autogenous red marrow and cancellous bone (3) MWF with beta tricalcium phosphate (4) RP and curettage at 3, 6, 9 months. Monkeys were sacrificed after 1 year.
Results: Histometric measurements of the distance between the CEJ and the apical termination of the junctional epithelium showed that there was no statistical difference between the operated and the control sites in any of the four groups of animals. Collagen fibers within the connective tissue adjacent to the epithelial lining were parallel to the root surface. A minimal amount of new cementum (0.3mm) was formed coronal to curette mark, in a few specimens of each group.
BL: Healing following the four different periodontal regenerative procedure resulted in the formation of an epithelial lining along the treated root surfaces with no connective tissue attachment.
Particle Size
P: To determine if particle size is a factor to be considered in the evaluation of the osteogenic activity of allogenic freeze-dried bone (FDBA) and, if so, whether small particles enhance or inhibit osteogenesis.
M+M: Six adult Rhesus monkeys were used in this study, and secured in their femurs were plexiglass diffusion chambers containing large particle (1000-2000μm) FDBA plus marrow and small particle (100-300 μm) FDBA plus marrow. Control chambers contained either marrow alone or were left empty. Two monkeys were given injections of oxytetracycline hydrochloride at 5 and 7 weeks to obtain intravital osseous labeling. All chambers were removed after 8 weeks. Ten chambers were evaluated for new bone formation by fluorescent microscopy. The contents of 15 additional chambers were evaluated by single blind technique for the presence or absence of bone resorption and ossification.
R/DISC: Nine of the small particles plus marrow chambers contained tissue with a firm consistency suggestive of calcification, seven of nine exhibited “reactive bone formation.” Nine of the large particle plus marrow chambers contained tissue having a firm consistency, but only four of the nine exhibited “reactive bone formation”. Significantly more new bone formation associated with small particle FDBA plus autogenous marrow than with large particle FDBA plus autogenous bone marrow. In addition, small particle FDBA plus autogenous bone marrow display more resorption than large particle FDBA plus bone marrow.
Possible reasons for superiority of smaller graft particles: A. reduction of bone to a smaller particle size increases the surface area around which more bone may form B. an increase in surface area, with an increase in osteoclastic activity could result in enhanced osteogenic induction. C. small graft particles could stimulate osteogenesis by increasing the number of “pores”(resorption cavities). D. small particles of FDBA could enhance necrosis of marrow with corresponding release of osteogenic substances.
BL: Smaller particles plus autogenous marrow enhance osteogenesis when compared to larger particles with autogenous marrow. Particle size is a variable to be considered when comparing the osteogenic potential of FDBA.
P: To provide data on the particle size of different grafting materials that are in vogue
M&M: Different bone grafting materials were gathered to compare particle sizes. Autogenous materials were obtained by high speed burs, low speed burs, and hand chisels (bone blending done on one group). The freeze-dried bone allograft was obtained from a tissue bank. Ceramic-like materials that were evaluated include Calcitite, Periograf, Synthograf, and Durapatite. Ten particles of each sample were measured and, at least 6 samples of each material were evaluated. The samples were studied under a light microscope and MOPP-3 digitizer.
R: All of the materials fall between 0.3-0.5 range (which is within the range felt most appropriate for periodontal use according to several articles in the literature). Bone blending yielded the smallest particle size (0.2mm), while hand chisels had the largest and most inconsistent particle sizes (1.6 +/- 2.2mm).
Material # of samples Long dimension Short dimension
Bone blend 8 210.8 +/- 138.1 105.1 +/- 72.9
Synthograft 15 302.7 +/- 106.9 223.3 +/- 84.9
High speed bur 20 351.1 +/- 213.7 198.1 +/- 123.3
Low speed bur 17 527.0 +/- 360.2 299.3 +/- 232.1
Freeze-dried bone 6 551.3 +/- 352.4 306.9 +/- 161.7
allograft
Periograf 7 519.1 +/- 126.6 341.4 +/- 86.6
Druapatite 11 538.3 +/- 146.4 359.3 +/- 84.9
Calcitite 6 520.7 +/- 93.5 386.5 +/- 67.1
Hand chisel 18 1559.6 +/- 2203.5 783.6 +/- 557.0
BL: With respect to particle size, these materials are acceptable for periodontal grafting, although bone blending is advisable when bone is harvested with hand chisels.
P: To compare the bony fill of human intrabony periodontal defects grafted with either 250 to 500 or 850 to 1,000.
M&M: 11 patients were included. Each pt had 2 similar interproximal 2-wall, wide 3-wall, or combination 2 and 3-wall defects 3mm deep adjacent to teeth with normally responsive pulp tissue. No control ungrafted defect included. All patients received initial therapy (OHI, SRP), re-evaluation (4-6 weeks), were prescribed doxycycline 100mg x 11 days starting 1 day pre-op, ibuprofen 800mg starting 1hr pre-op and CHX for post-op use. Soft tissue measurements were performed immediately before sx. Distance from reference point to free gingival margin and base of the pocket was measured. FTFs were reflected, granulation tissue removed, roots debrided, no chemical conditioning was performed. Distance from fixed point to the alveolar crest and base of the defect was measured during sx. . Experimental defects were grafted with DRDBA. The graft material was processed from cortical bone of one donor into particle sizes of 250-500 or 850- 1,000. Flaps were closed. Post-op treatment (OHI, supra-g debridement) was provided at 1, 2 and 4 weeks and then every 1-2 months until re-entry. Grafted sides were re-entered 6 months post-op.
R: No SSD between initial probing and intrabony defect depth for the small and graft particle graft sites. The bony defect fill was 1.32mm (38.6%) for the small particle group and 1.66mm (34.9%) for the large particle group. NSSD between the two groups. No significant differences in CAL gain, REC or alveolar crest resorption.
Disc: Factors related to particle size that could cause difference in healing include interparticle spacing, surface area and exfoliation of osseous graft particles, Shape and size of the particles can affect interparticle spacing when DFDBA is packed into osseous defect. A minimum interparticle spacing of approximately 40 to 200 is necessary for the ingrowth of vascular and bony tissues. Narrower spacing may inhibit revasclularization and retard healing. Larger particle sizes of autogenous bone grafts may have an increased tendency to be exfoliated.
BL: NSSD in bony defect fill for the two particle sizes measured. Therefore, the clinician’s choice of particle size is a matter of personal preference than can be based on clinical handling characteristics.
What are the general principles of regeneration? Is this a predictable procedure? What surgical characteristics or techniques can increase the predictability of surgical success?
P: To attempt to establish new attachment by controlling epithelial proliferation with use of free palatal or gingival grafts to cover intrabony defects after treatment.
M+M: 88 intrabony lesions in monkeys of combined three, two, and one wall defects. Incisions are made parallel to and 1mm below the free gingival margin at the buccal and palatal aspect of the intrabony defect. Interproximally the incisions directed parallel to crest of bony walls of defect. The wedge of tissue created by these incisions is removed and root surface planed. Two vertical incisions made on either side of defect and a split thickness flap performed at buccal and palatal. Autogenous cancellous graft transplanted from edentulous ridge and then defect covered with free palatal graft. The graft was sutured to periosteum and the attached gingiva. Tefla and Coe pack dressing applied for 2 weeks. Results evaluated 3 and 6 months post-op.
R: 60% of intrabony defects regenerated completely with new attachment compared to 40% with conventional flap. With conventional flap 60% had residual PD >3mm, while only 10% of defects treated with soft tissue grafting had residual PD>3mm.
BL: Free soft tissue grafts result in markedly more new attachment in intrabony defects than conventional flap surgery.
CR: No control group or conventional flap group discussed in the material and methods of article; could be comparing their own conventional flap statistics from prior studies but not clear. No statistics.
The regenerative potential of the periodontal ligament
Purpose: to examine if new Cementum and new attachment may form during healing of a wound prepared in such a way that preference is given to periodontal ligament cells to repopulate the wound area
Materials and methods
Three adult monkeys, 8 weeks prior to experiment they were scaled and polished every 14 days. At the end healthy gingival conditions were established
Max lateral incisors and mandibular canines were used. U shape incision was made and flap was reflected to expose buccal bone.
Within an area extending from approximately the level of half the root length to a level 2mm apical to the marginal bone crest, the buccal and proximal bone was removed (fenestration).
The root surface was curetted to remove all Cementum, small notches prepared
A Millipore filter was placed to cover fenestration, flap sutured.
Monkeys were sacrificed at 6 months and histology was performed.
Results
In all specimens, Cementum with inserting connective tissue fibers had formed on the curetted area.
The newly formed Cementum was usually thicker in the apical part than at a more coronal level.
In the one specimen where the Millipore filter had become displaced, Cementum was only seen within the apical notch while CT without signs of attachment was located in contact with the area.
Significant bone regeneration had occurred ranging from 0 to 3.9mm
In those areas where Cementum and bone had formed, a functionally oriented PDL had been reestablished.
Discussion
The present study demonstrated that new Cementum can form and a CT attachment can develop on root surfaces deprived of their original Cementum and PDL.
In 50% of the specimens, healing in the coronal part was characterized by CT adhesion, without signs of Cementum formation.
Cementum formation following surgery, must have originated from the PDL in the apical border of the wound.
Newly formed bone is presumably originated from the edges surrounding the prepared wound.
Mellonig 1990 No ARTICLE
Purpose: To describe periodontal bone graft technique.
Objectives: -Pocket reduction (clinical)
-Bone repair (clinical)
-New attachment (histological)
Patient selection: - Good physical health
- Positive attitude towards therapy
-Acceptable level of plaque control
- Patient should be committed to a maintenance care program
Defect selection: - Almost any intraosseous defect
-Deep pockets with persisting BOP.
-AL over time
-Intraosseous defects may not always be present radiographically
Contraindications: - Extensive gingival recession and/or soft tissue cratering
Anesthesia: Depending on the site (nerve block or local infiltration), epinephrine should be contained to achieve hemostasis.
Flap design and reflection: - Intrasulcular incisions at least one tooth mesial and distal to the defect and as far as possible to the interproximal, maximum tissue conservation is the goal. Vertical incisions avoided if possible
-Full thickness flap reflected 2-3 mm beyond the limits of the defect.
Soft tissue debridement: -All granulation tissue should be removed using ultrasonic instrumentation and hand instruments, after that bleeding within the defect should rapidly subside.
- If bleeding cannot be controlled success of the graft may be jeopardized and an alternative treatment should be considered.
-Root planing and measurements of the dimension of the defect are then performed. This will provide a means of comparison from which to determine the amount of alveolar crest resorption and bone repair.
-Intramarrow penetration should be performed if the defect is surrounded by cortical bone.
Graft insertion: -If the patient has a sufficient intraoral donor sites, a bone autograft may be used (healing extraction sockets, edentulous ridges, exostoses).
-If autograft cannot be obtained a properly processed bone allograft with sterile saline added can be used. Excess saline is absorbed with a dry gauze.
-Graft should be placed till the level of existing bone walls. An overfill approach can be used if supracrestal bone apposition is the goal, but this is extremely unpredictable and the additional flap may impede the flap closure.
Flap closure: - The site should be completely covered by soft tissue. Limited thinning of the tissues, scalloping in the lingual or buccal side, slight reduction of the width of interproximal bone can be used for this reason.
Suturing: -Vertical mattress or interrupted sutures, with a monofilament suture such as nylon.
-Periodontal dressing is placed, analgesics and antibiotics (tetracycline the drug of choice 250mg/every 6 hours/10 days.
Postoperative management: - Patient seen in one week for suture removal and plaque control. Wound is dressed for another week. After the second week and the removal of dressing, patient should be instructed in plaque control measurements. Chlorhexidine rinse should be prescribed.
-Sometimes soft tissue craters are present, and if they remain at 6 months, gingivoplasty can be used to correct them.
Maintenance: -Patient is seen every two months for the first six months and then every three months.
-Rarely are maintenance visits extended beyond the 3-month interval for the bone graft patient.
Reevaluation: -Clinically at 6 months. If the bone graft site does not fill completely with bone, a second bone graft procedure may be used, according to the clinician’s judgment.
P: A review article on synthetic bone grafts in Perio.
Disc: Alloplastic graft materials (AGM) can be classified as Resorbable (Plaster of Paris, calcium carbonate, tricalcium phosphate, resorbable HA), & Nonresorbable (dense HA, porous HA, Bioglass). Particle size 300-500 um.
Indications:
Deep infrabony defects (wide 2-3 walls &combination), need for increased bone support for a tooth, LAgP, maintenance of an aesthetic gingival margin height.
Techniques:
Remove all etiological agents- local and systemic
Stabilize teeth- temporary, provisional or permanent
Flap design for primary closure
Degranulation of defect
Root preparation
Cortical perforation
Presuturing
Condense graft material
Fill to a realistic level
Good tissue coverage
Periodontal dressing
Antibiotic coverage- pre-surgical TTC (10 days).
AGM may be used as autograft extenders, being added to available autogenous bone to provide a sufficient total volume of graft material. They may also been used as carriers for growth factors, antibiotics or other substances.
A mean defect fill of about 60-70% has been shown with all the listed materials, with no essential difference between them. Failures & complete fill 10% of the time. Pocket reduction & growth of alveolar bone are commonly observed. True histologic new attachment is less frequent & less predictable.
BL: More important than the type of graft material is proper case selection & appropriate surgical management of the defect & root surface.
P: To describe the "papilla preservation technique" and report clinical success in 25 cases in which an allograft was used.
Tech: Extension of bone defect is determined by probing. Sulcular incisions around each tooth with no incisions through the interdental papilla. Lingual or palatal semilunar incision across each dental papilla dipping apically from the line angles at least 5mm from the gingival margin, (& at least 3 mm away from IP bny defect). The interdental tissue is dissected and elevated intact with the facial flap. In large graftable defects, the semilunar inc is made on the facial aspect. Careful dissection of epi & granulation w/, grafting as necessary. Author advocates cross mattress sutures and dressing (replaced after one week).
BL: Authors report using this technique with 25 cases all of which healed with no adverse evenet and had papilla fill at 6mo. This flap design can be used in anterior and posterior regions. Wound healing occurs by primary intention w/o evidence of immediate graft exfoliation nor development of interdental craters (which makes it easier for patients to maintain optimal OH). Technique could also be used w/o grafts to improve post-op soft tissue contour. The determining factor is the space between teeth.
Purpose: Retrospective study evaluating clinical results of the minimally invasive surgery (MIS) approach for bone grafting.
M&M: Bone grafts of DFDBA& membrane at 194 sites in 87 pts who routinely had regular SPT after active treatment. Baseline and re-evaluation after phase I therapy measurements: PD, CAL, furcation, mobility. Occlusal adjustment if needed. A prognosis of good to fair was given to teeth that were projected to be retained as functional units postsurgically (PD 2-4 mm). A prognosis of questionable to poor was assigned to teeth with the possibility of being marginally or non-functional after surgical treatment (postsurgical PD of 5 mm or more). MIS using small incisions and minimal flap reflection. Mean healing time was 21.7 months. Post surgical data collected at time of SPT appointments that occurred within 6-month period.
R: Mean improvement for PD was 4.58mm (SSD) and for CAL was 4.87mm (also SSD), regardless of initial prognosis. The post surgical gingival margin was at or within 1mm of CEJ for 53% of sites treated.
BL: MIS tech yielded good results that were equivalent to more traditional surgical approaches utilizing longer incisions and greater reflection & is effective in reducing PD.
Purpose: To evaluate the effect of intramarrow penetration on the rate of bone neo-genesis in protected spaces created on the calvarial bone using occlusive titanium domes in rabbits.
M&M: Sixteen rabbits were used in the study. In each rabbit, 2 standardized circular 1mm deep slits were prepared in the bone, one on each side of midline using trephine. Within one of the slits, the external cortical surface of the skull bone was mechanically perforated using a carbide round bur (experimental group), and the other slit was left intact (control group). At the same time, 2 prefab titanium domes were anchored in the prepared slits.
The animals were divided into 4 groups and were then sacrificed at 10, 21, 42, 60 days. Specimens were assessed for the percentage of bone fill and density of the newly formed bone within the boundaries of the domes.
Results: Histologic analysis showed increased bone neo-genesis in the experimental group at 10, 21, 42 and 60 days. In experimental sites, the formation of new bone trabeculae was predominantly at the perforations of outer cortical layer, while in control sites seems to be originated from the endosseous area at peripheral circular slits prepared to retain the domes.
Bone density was consistently higher in the experimental group at all healing intervals.
Conclusion: Intramarrow penetration accelerates initial bone neo-genesis and results in increase in bone fill and density, suggesting its use can be beneficial in bone regenerative procedures.
P: To provide an overview of bone and bone substitutes intended for periodontal reconstructive therapy and their biological potential.
D:The ideal bone graft should be able to trigger osteogenesis, cementogenesis and formation of a functional periodontal ligament. Osteogenesis, the formation of mineralized bone by transplanted osteoblasts, is only achieved with autogenous grafts.
Autogenous grafts: iliac bone was of initial interest, but the discovery of root resorption (although relatively low frequency) limited its clinical use. Intraoral autogenous grafts are usually utilized in perio sx since this takes place usually in an outpatient environment. While autogenous bone is still the standard, the relatively limited amount of conveniently available bone and the harvest time involved in obtaining these grafts have led clinicians to utilize other bone replacement grafts.
Allogenic grafts: from the same species
-Freeze-dried bone allografts (FDBA) are osteoconductive. Studies have shown that mixing FDBA with autogenous enhances its osteogenic potential.
-Demineralized freeze-dried bone allografts (DFDBA) were created because the bone mineral blocked the effect of the factors stimulating bone growth sequestered in bone matrix including BMPs. The addition of autogenous to DFDBA has not been shown to significantly increase its oteogenic potential. DFDBA from younger animals has been shown to be more osteogenic than form older animals. DFDBA is osteoconductive as well as osteoinductive. At this time, DFDBA is the only bone replacement graft proven to result in perio regeneration in a controlled human histological study.
Xenografts: from another species; osteoconductive
-Bone derived replacement grafts: biocompatible and risk free from disease transmission. Materials marketed in the US certify that they originate in the US since the cattle has remained unaffected from bovine spongiform encephalopathy. Commercially available bovine bone is processed to yield natural bone mineral minus the organic component. Thse products are structurally similar to human bone, with improved osteoconductive capability compared to synthetically derived materials. Anorganic bovine bone is hydroxylapatite “skeleton” (it is deproteinated) that retains the macroporous and microporous structure of cortical and cancellous bone after chemical or low-heat extraction of the organic component.
-Corralline calcium carbonate: Biocoral is calcium carbonate obtained from a natural coral and is composed primarily of aragonite. Its pore size is 100-200 micrometers, similar to the porosity of spongy bone. This material is resorbable and no fibroencapsulation has yet to be reported.
Alloplastic grafts: synthetic (if regeneration is required, other materials are recommended); defect fillers; osteoconductive
-Bioceramics (alloplasts comprised primarily of calcium phosphate, with the proportion of calcium and phosphate similar to bone)
-Tricalcium phosphate: a porous form of calcium phosphate, the most commonly form used being -tricalcium phosphate. This material generally becomes encapsulated and does not stimulate bone growth, however some bone deposition has been reported. This material is partially resorbable.
-Hydroxyapatite: hydroxyapatite is the primary mineral component of bone. Its synthetic form has been marketed in various forms: porous non-resorbable, dense or solid non-resorbable, and resorbable (non-ceramic, porous). Its resorbability depends on the temperature at which it is processed. When prepared at high temperatures (sintered), it is non-resorbable, non-porous, dense, and has a larger crystal size.
-Bioactive glasses: (Perioglas, Biogran) Bond to bone through the development of a surface layer of carbonated hydroxyapatite. It has been theorized (at this point in time) that these bioactive properties guide and promote osteogenesis, allowing rapid formation of bone. In a study by Fetner (developer/part owner), Perioglas has good manageability, hemostatic properties, and besides being osteoconductive may also act as a barrier to retard epithelial downgrowth. These two materials “guide” osteogenesis.
Morphological and biological implications: It would seem rational to suggest that particles too large in size will resorb at a slower rate and offer an overall reduced surface area, while particles too small may induce inflammation, be readily resorbed of phagocytosed and result in an interparticulate space of a reduced dimension that would not be conducive to cellular migration and ingrowth. However, to date there is little or no histological evidence to support an ideal particle size.
Technical implications:
-Preparation of graft material: it is suggested to wet grafts with the pt’s own blood instead of saline, which may hinder vascular infiltration of the saturated particles.
-Promotion of a bleeding surface: usually accomplished by proper defect debridement. IMP may be needed to encourage bleeding.
-Presuturing: loose placement of sutures, left untied prior to filling the defect reduces the possibility of displacing the bone graft during suturing.
-Do not overfill (not realistic to achieve bone growth over bony walls and may complicate primary closure).
-Antibiotic coverage: increasing evidence supports the use of antibiotics when bone grafts are used. The author prefers tetracycline due to its suppression of plaque due to its wide spectrum, attraction to healing wound sites, and concentration in GCF.
Clinical comparison: A mean defect fill of 60-70% can be anticipated with similar clinical effectiveness among bone replacement grafts. Surgical debridement alone yields between 10-30% defect fill. Overall, PD reduction and ALgain are similar for all bone replacement grafts.
BL: With source limitations for autogenous bone and concers regarding allogenic bone, the role of bone substitutes will likely increase. Except for fresh autogenous bone, bone replacement grafts are no osteogenic, nor can they be reliable considered truly osteoinductive, but instead are mostly osteoconductive, providing a scaffold for bone deposition.
P: To review the literature on graft materials and to offer a technique for the successful use of bone grafts.
DISC:
Patient selection: good physical health, acceptable level of OH, committed to long-term maintenance program, ideally non-smoker.
Defect selection: predictability of regeneration increases as the number of remaining walls increases, 3-wall defects>2-wall defects>1-wall defect.
Preoperative preparation: patients should perform plaque control to an acceptable level, occlusal adjustment or splinting should be accomplished prior to sx to reduce or eliminate excessive mobility. Pre-procedural rinse with antimicrobial agent (0.12% CHX for 30sec) immediately prior to sx can help reduce intraoral bacteria.
Flap design: preservation of flap tissue is important for regenerative procedures to ensure coverage and containment of the graft post-sx. Sulcular incision is performed on facial and lingual with IPx space being conserved by either papilla preservation technique or extending the incision interdentally as far as possible. Flap extended at least one tooth mesial and distal of the graft site, A vertical incision may be used to avoid sx at adjacent healthy areas. Flap should be reflected to allow complete visualization of the intrabony lesion while minimizing trauma to the soft tissue. Any granulomatous tissue adherent to inner surface of the flap or papillae should be removed, which maximizes space for graft. Excessive thinning can compromise blood supply and flap survival.
Defect or root debridement: defect should be debrided of all soft tissue using hand, ultrasonic and rotary instruments. Roots should be debrided, any clinical affected cemental surface and root anomalies should be removed. A saturated solution of citric acid or TCN may be applied to root surface to biologically enhance regeneration through removal of the smear layer and residual colonies of bacteria. Excess solution should be removed from the cotton pellets to minimize cellular damage to the adjacent hard and soft tissues. Intramarrow perforation may enhance regeneration, It is intended to enhance revascularization and incorporation of the graft. Also, bone marrow serves as a repository for the pluripotent progenitor cells essential for regeneration
Graft management: An allograft material should be placed in a sterile dish and covered by a saline saturated gauze to avoid dehydration. TCN may be added to the graft material to enhance osteogenic acitivity. The graft is next delivered to the bony defect. Light pressure should be used to maintain space between the graft particles to allow revascularization of the site. The defect should be filled or slightly overfilled to maximize regeneration while not compromising flap closure or vascular supply.
Flap closure: The goal of the flap management is to obtain tension-free primary closure over the entire graft or defect complex. A monofilament or Teflon suture using vertical mattress or an interrupted technique should be used to minimize bacterial wicking. After suturing, slight pressure on the facial and lingual flaps is applied to minimize the clot beneath the flap. It is optional to place a surgical dressing to protect the wound.
Post-op management: Administration of antibiotics beginning immediately post-sx and use of antimicrobial rinse is thought to aid in plaque control. For the first 4-6 weeks patients should refrain from brushing the surgical area to prevent disturbance of the clot. Sutures are retained as long as they maintain closure and do not contribute to plaque accumulation and inflammation. Post-op visits include plaque removal and reinforcement of OH. Periodontal probing should not be done prior to 6-12 months.
A review of autogenic, synthetic and allogenic materials used in intrabony defects is done with authors and comparative data (PD changes, CAL changes, when re-entry done).
Grafting options
Autogenous grafts: intraoral (maxillary tuberosity, exostoses, healing wounds, extraction sites, edentulous ridges) or extraoral donor sites (iliac cancellous bone). Hiatt & Schallhorn reported an average bone fill of 3.44mm in 166 osseous defects grafted with intraoral cancellous bone and marrow.
Synthetic grafts: Act almost exclusively as biological fillers with scant bone fill and very limited connective tissue regeneration Absorbable (ceramics, beta tricalcium phosphate, hydroxyapatite, calcium sulfate and calcium carbonate. Non-absorbable (porous hydroxyapatite, dense hydroxyapatite, bioglass). Yukna et al demonstrated up to five years of clinical stability following grafting with hydroxyapatite.
Allogenic bone grafts: frozen cancellous iliac bone and marrow, cryopreserved bone from the head of a femur, freeze-dried bone allograft and demineralized freeze-dried bone allograft. Borghetti et al found 60% defect fill at grafted sites with cryopreserved allografts from femur heads as compared to 29% fill for non-grafted sites. A controlled clinical trial by Mellonig comparing DFDBA to non-grafted sites demonstrated greater average bone fill (2.57mm versus 1.53mm) for the grafted sites.
BL: There is substantial clinical and histological evidence that supports the concept that autogenous bone grafts and DFDBA grafts are effective regenerative materials in the tx of intrabony defects. Long term evaluations suggest the regenerative gains achieved remain clinically stable. Synthetic grafts may result in improved PDs and CALs but have not yet demonstrated the ability to initiate or enhance the formation of a new attachment apparatus.
P: To assess the efficacy of bone replacement grafts in the treatment of periodontal osseous defects compared to open flap debridement and other surgical therapies.
M+M: Systematic review. Focus question: In patients with periodontal osseous defects, what is the effect of bone replacement grafts compared to other interventions on clinical, radiographic, adverse, and patient centered outcomes? Reviewed MEDLINE (1966-2002) and EMBASE (1974-2002) for randomized control studies. Search limited to human studies in English language populations. Meta-analysis conducted.
R: 49 studies met eligibility requirements and provided clinical outcome data on intrabony defects following grafting procedures. 17 studies provided clinical outcome data on bone replacement grafts materials for treatment of furcation defects.
Tx of intrabony defects:
Bone grafts increased bone level, reduced crestal bone loss, increased CAL, and reduced PD compared to OFD
No difference in clinical outcome between allograft and calcium phosphate (HA) grafts
Bone grafts in combination w/ membrane increased CAL and reduced PD compared to graft alone
Tx of furcation defects:
Insufficient studies of comparable design to submit data to meta-analysis.
Data from these studies indicate positive clinical benefits with use of grafts in class II furcations.
Histo outcome:
DFDBA supports formation of new attachment in intrabony defects, OFD results in perio repair w/ LJE
Autogenous and demineralized allogeneic bone grafts support new attachment
Limited data shows xenogenic bone grafts supporting formation of new attachment
Virtually all data suggest alloplastic grafts lead to repair rather than regeneration
BL: Bone replacement grafts demonstrate clinical improvement in periodontal osseous defects compared to OFD alone.
What are the characteristics of defects that allow for more predictable regeneration?
Cortellini ARTICLE
Periodontal regeneration of human infrabony defects II reentry procedures and bone measurements
Purpose: to evaluate the osseous healing response following GTR treatment in deep infrabony defects.
Materials and methods
40 infrabony defects in 23 patients
Full thickness flap was elevated, debridement of the defect, measurements were taken, CEJ to Bottom of defect, CEJ to the most coronal extension of the interproximal bone.
Impressions of the defects were taken.
Teflon membranes were used to isolate the defects and overlap surrounding bone.
Membranes were removed by elevating a partial thickness flap and the newly formed granulation tissue was measured.
Surgical reentry one year following membrane removal.
Intrasurgical measurements were taken as well as impressions of defects. Histology was performed.
Results
Radiographic measurements decreased from 11.3 to 8.2.
57.5% of sites gained 4mm or more in probing bone level
No sites lost supporting bone following treatment.
Radiographic bone gain was observed in 35% of sites.
BL: on the healing of deep 3,2 and 1 wall combination defects.
GTR resulted in gain of probing bone level of 4.3mm
87.5% of treated sites showed gain of PBL 2mm or more
On average 0.4mm of marginal crest resorption was evidenced
On average 73% of original defect was filled after 1 year
3 wall, 2 wall and 1wall defects were filled 95%, 82 %, 39% of original PBL respectively
Kim 2004 ARTICLE
Purpose: To histologically evaluate the healing response following gingival flap surgery in experimentally produced 1-, 2- and 3-wall intrabony defects in dogs to determine the influence of defect configuration on periodontal wound healing/regeneration.
Materials and methods: Six 2-years old beagle dogs. Throughout the study they were fed with soft diets to reduce chances of mechanical interference with healing during food.
Mandibular 1st and 3rd molars were extracted and extraction sites healed for 2 months. The remaining dentition received dental prophylaxis. During the surgery lingual and buccal flaps were elevated and “box-type” 1, 2 and 3-wall defects (4x4x4mm) were created three in either the left or right side of the mandible. A notch was created at the root surface of the adjacent teeth at the base of the defect. Primary tension – free closure was accomplished, and sutures were removed ten days later.
Post – surgery management included antibiotics IM, soft diet and 2% chlorhexidine solution. Animals were euthanized 8 weeks after surgery.
The following histometric measurements were made: defect height (DH: alveolar crest to apical extension of reference notch), junctional epithelium (JE: CEJ to apical extension of JE), connective tissue adhesion (CT: apical extension of JE to the coronal extension of cementum regeneration), cementum regeneration (NC: apical extension of reference notch to coronal extension of newly formed cementum) and bone regeneration (NB: apical extension of reference notch to the coronal extension of newly formed bone along root surface). Statistical analysis was performed.
Results: Histologic evaluation revealed limited inflammatory cell infiltration in defect sites.
JE extended more apically in the 1-wall compared to 3-wall defects.
Marked bone regeneration was observed in 3-wall defects as well as new cellular cementum. All defect sites maintained PDL space. Limited root resorption was observed and no ankylosis.
The results between the different 2-wall defects may vary depending on where the bone walls are and the support they provide to the soft tissues.
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BL: Healing of intrabony defects is positively correlated to the number of bone walls limiting the defects. Increasing numbers of bone walls is associated with a significant increase in bone and cementum regeneration and a decrease in in formation of junctional epithelium.
What patient characteristics can influence the outcome of periodontal regeneration? Which can we help control? What would a recommended recall interval be for patients having bone grafting?
Tonetti 1995 ARTICLE
P: To examine the effect of cigarette smoking on the healing response following GTR in deep infrabony pockets.
M&M: 71 defects in 51 patients, at least 6mm infrabony defect assessed by radiograph and PD. PTs underwent initial therapy, 3 mo baseline measurements and surgical procedure followed, GTR with Teflon membranes. 20 patients (32 defects) smoked more than 10 cigs per day, while 31 patients (39 defects) did not smoke. Clinical measurements taken at baseline, at membrane removal, and at 1 yr follow up.
R: OH was good for both groups but smokers had significantly higher full mouth plaque scores. No diff was noted between smokers and non-smokers in terms of % tissue gained at membrane removal. At the 1year follow up, smokers gained significantly less probing attachment level than non-smokers (2.1+/- 1.2mm compared with 5.2 +/- 1.9mm). When controlled for OH of the patients and the depth of the infrabony defects, smoking itself was determined to be a significant factor in determining the clinical outcome.
Risk assessment- Smoking resulted in a 4.3 fold increase in risk for a site to be a “looser” site.
BL: Smokers have a significantly greater risk than non-smokers to display reduced probing attachment level gain following GTR. Smoking is associated with reduced healing response after GTR treatment and may be responsible, at least in part, for the observed results.
Cortellini 1994 ARTICLE
P: To assess the role of supportive periodontal care in the maintenance of gained clinical attachment obtained after surgical therapy according to the principles of GTR in deep infrabony defects
M&M: 40 deep infrabony defects in 23 subjects were treated by GTR (SRP, OHI, GTR – using Gore-Tex, membrane removal at 4-6 weeks, monthly recall for 1 year). Plaque scores, BOP, PD, recession, PAL were recorded at baseline (1 week before surgery), 1 and 4 years follow up. Subgingival plaque samples. Two experimental groups: A – SPT every 3 months after 1 year to 4 years, B – Sporadic, treatment-oriented dental care after 1 year to 4 years.
R:
- NSSD in BOP and plaque scores at 1-year between group A and group B. At 4 years, group B had greater BOP SSD
- NSSD in PAL, PPD and recession at baseline and 1 year evaluation between 2 groups. Group B had greater PAL loss SSD when comparing results at 1 and 4 years and NSSD between baseline and 4 years
- Marked reduction of PPD was observed in both groups after GTR (Group A 8.5 mm to 1.9 mm and Group B 7.2 mm to 2.2 mm). At 4 years, Group B had more PPD at 4 years (5.1 mm vs 2.7 mm)
- Significant recession of gingival margin was observed between the baseline and 1 year evaluation in both groups. The position of the gingival margin did not significantly change between the 1-year and 4-year evaluations in both groups.
- BOP was detectable in 16/18 sites of group B and 2/22 sites of group A. Pg/Pi were present in 14/18, 16/18 sites of group B, while they were detectable only 5/22, 6/22 sites of group A
BL: CAL gain by GTR in vertical defects could be maintained for at least 4 years with a regular supportive periodontal care program
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