Clinical comparison of microporous biocompatible composite of PMMA, PHEMA and calcium hydroxide grafts and expanded polytetrafluoroethylene barrier membranes in human mandibular molar Class II furcations. A case series.

BACKGROUND: Class II furcations present difficult treatment problems. Several treatment approaches to obtain furcation fill have been used with varying success. METHODS: The response of mandibular Class II furcations to treatment with either a microporous biocompatible composite of PMMA (poly-methyl-methacrylate), PHEMA (poly-hydroxyl-ethyl methacrylate) and calcium hydroxide graft synthetic bone (HTR) replacement graft material; ePTFE barrier membrane; or a combination of the two was evaluated in trios of mandibular molars with Class II furcations in 8 patients with moderate to advanced periodontitis. Following initial preparation, full-thickness flaps were raised in the areas being treated, the bone and furcation defects debrided of granulomatous tissue, and the involved root surfaces mechanically prepared and chemically conditioned. By random allocation, HTR, ePTFE, or a combination of both was placed into and/or fitted over the furcations, packed and/or secured in place, and the host flap replaced or coronally positioned with sutures. Postsurgical deplaquing was performed every 10 days leading up to ePTFE removal at approximately 6 weeks. Continuing periodontal maintenance therapy was provided until surgical reentry at 6 months for documentation and any further necessary treatment. RESULTS: Direct clinical measurements demonstrated essentially similar clinical results with all 3 treatments for bone and soft tissue changes. There were no statistically or clinically significant differences except for better horizontal amount and percent defect fill with HTR alone. Four of 8 furcations became Class I clinically with HTR alone, 5 of 8 became Class I with ePTFE alone, and 5 of 8 with combination treatment. The only complete furcation closure occurred with HTR. CONCLUSION: The findings of this study suggest essentially equal clinical results with HTR bone replacement graft material alone, ePTFE barrier alone, and a combination of the two in mandibular molar Class II furcations. However, a real difference may not have been detected based on the small number of subjects in the study.

Clinical evaluation of acellular allograft dermis for the treatment of human gingival recession.

BACKGROUND: Periodontal root coverage procedures to treat recession areas are indicated for unesthetic, exposed, and/or painful root surfaces. Many methods, most using autogenous soft tissue grafts, have been utilized, but with associated morbidity at the donor sites. An alternative donor material would reduce the morbidity and provide for sufficient available donor tissue. METHODS: An acellular allogeneic dermal connective tissue matrix (AD) and autogenous palatal connective tissue (CT) were compared as subepithelial grafts for the treatment of gingival recession. Twenty-two patients with similar isolated gingival recession of > or = 2 mm on 2 separate teeth were treated with the subepithelial graft technique. Exposed roots were hand root planed only and, by random allocation, either a fitted AD or fitted CT graft was secured in place and covered by coronally positioned flaps. RESULTS: Mann Whitney U test analysis found the following changes at 6 months for AD and CT, respectively, compared to presurgical conditions: root coverage of 1.7 +/- 1.2 (65.9%) and 2.2 +/- 1.1 mm (74.1%) (both P<0.01), increase in keratinized tissue (KT) of 1.2 +/- 1.3 and 1.6 +/- 1.9 (both P<0.01), and an increase in gingival thickness with both; 83.2% of expected root coverage was obtained with AD and 88.6% with CT (P= 0.43). There were no significant differences between treatments for any parameter. Global assessments by clinicians and patients suggested a more esthetic clinical result with AD. CONCLUSIONS: These results suggest that acellular allogeneic dermal matrix may be a useful substitute for autogenous connective tissue grafts in root coverage procedures.

Gingival, dermal, and periodontal ligament fibroblasts express different extracellular matrix receptors.

BACKGROUND: Fibroblasts are the predominant cells of the periodontal ligament and the gingiva and have important roles in the function and regeneration of the tooth support apparatus. The goal of this study was to investigate the possible differences in the adhesion properties and expression of extracellular matrix (ECM) receptors among different fibroblast populations. METHODS: The adhesion of gingival (GF), dermal (DF), and periodontal ligament fibroblast (PDLF) cultures to ECM proteins (fibronectin, laminin, vitronectin, RGD peptide, collagen type I, and collagen type IV) adsorbed to tissue culture plastic was evaluated fluorometrically. Quantitative reverse transcription-polymerase chain reactions (RT-PCR) were performed using primers specific for 19 integrin subunits to quantify ECM receptor transcript expression. RESULTS: Our data demonstrated that GF and PDLF adhere to vitronectin and collagen types I and IV more avidly than do DF. PDLF adhered well to laminin, whereas GF and DF did not. Quantitation of integrin expression demonstrated that the different fibroblast types expressed different integrin transcripts, further demonstrating their innate differences. CONCLUSIONS: The 3 fibroblast types studied behave differently and expressed different ECM receptors. However, gingival fibroblasts and periodontal ligament fibroblasts are more similar in their attachment and integrin expression than either is to dermal fibroblasts. Therefore, experiments using DF will not necessarily be valid for oral tissues.

Clinical comparison of bioactive glass bone replacement graft material and expanded polytetrafluoroethylene barrier membrane in treating human mandibular molar class II furcations.

BACKGROUND: Class II furcations present difficult treatment problems and historically several treatment approaches to obtain furcation fill have been used. METHODS: The response of mandibular Class II facial furcations to treatment with either bioactive glass (PG) bone replacement graft material or expanded polytetrafluoroethylene (ePTFE) barrier membrane was evaluated in 27 pairs of mandibular molars in 27 patients with moderate to advanced periodontitis. Following initial preparation, full thickness flaps were raised in the area being treated, the bone and furcation defects debrided of granulomatous tissue, and the involved root surfaces mechanically prepared and chemically conditioned. By random allocation, PG or ePTFE was placed into or fitted over the furcations, packed or secured in place, and the host flap replaced or coronally positioned with sutures. Postsurgical deplaquing was performed every 10 days leading up to ePTFE removal at about 6 weeks. Continuing periodontal maintenance therapy was provided until surgical reentry at 6 months for documentation and any further necessary treatment. RESULTS: Direct clinical measurements demonstrated essentially similar clinical results with both treatments for bone and soft tissue changes. There were no statistically or clinically significant differences (e.g., mean horizontal furcation fill 1.4 mm PG, 1.3 mm ePTFE; mean percent horizontal furcation fill 31.6% PG, 31.1% ePTFE, both P>0.85). Seventeen of the PG treated and 18 of the ePTFE furcations became Class I clinically and 1 furcation completely closed clinically with each treatment. Intrapatient comparisons showed similar horizontal furcation responses with both treatments. CONCLUSION: The findings of this study suggest essentially equal clinical results with PG bone replacement graft material and e-PTFE barriers in mandibular molar Class II furcations. PG use was associated with simpler application and required no additional material removal procedures.

Collagen membrane resorption in dogs: a comparative study.

Guided tissue barriers using materials such as collagen are used in the hope of excluding epithelium and the gingival corium from the root surface or alveolar bone to facilitate regeneration. Convention suggests that the longer a membrane remains intact, the better the regeneration results. The purpose of this study was to determine the resorption rates of various collagen membranes in the oral cavity of dogs. Twelve adult mongrel dogs had three different collagen membranes (BioGide, AlloDerm porcine-derived, and AlloDerm human-derived) randomly inserted and secured into surgical pouches made in their palates. Full-thickness tissue punch biopsy specimens taken at 1, 2, 3, or 4 months after surgery were evaluated histologically for membrane intactness and other associated changes. At 1 month, all membranes had slight to moderate degradation. At 2 months, all membranes had moderate to severe degradation with the exception of one AlloDerm human-derived membrane that was intact. At 3 months, all membranes had severe degradation to not identifiable. At 4 months, all membranes had severe degradation to completely absent. Blood vessel penetration varied from none to moderate. Inflammation was found in only two samples. In the dog, all three tested collagen membranes showed slight to moderate degradation at 1 month and were severely degraded to completely absent at 4 months. Within the limits of transferring animal data to humans, clinicians need to be aware of these resorption rates when selecting membranes for guided tissue and bone regeneration.

Multi-center clinical comparison of combination anorganic bovine-derived hydroxyapatite matrix (ABM)/cell binding peptide (P-15) and ABM in human periodontal osseous defects. 6-month results.

BACKGROUND: Intraosseous periodontal defects present a particular treatment problem. New bone replacement grafts offer promise for improved results. METHODS: The role of a synthetic cell-binding peptide (P-15), combined with anorganic [corrected] bovine-derived hydroxyapatite bone matrix (ABM), was compared to ABM alone in human periodontal osseous defects in a controlled, monitored, multi-center trial. Following appropriate initial preparation procedures, flap surgery with defect and root debridement was performed. Two osseous defects per patient were treated randomly with each procedure after surgical preparation. Appropriate periodontal maintenance schedules were followed, and at 6 to 7 months, re-entry flap surgery was performed for documentation and finalization of treatment. RESULTS: T test and Mann-Whitney U analyses of patient mean values from 33 patients revealed that the combination ABM/P-15 grafts demonstrated significantly better mean defect fill of 2.9 +/- 1.2 mm (72.9%) versus a mean defect fill of 2.2 +/- 1.4 mm (50.67%) for defects treated with ABM (P<0.05). Other hard tissue findings showed similar clinically superior results with the use of ABM/P-15. Relative defect fill results showed 81% positive (50% to 100% defect fill) responses with ABM/P-15 and 67% positive responses with ABM. There were 3.5 times as many optimal results (> or = 90% defect fill) with ABM/P-15 and twice as many failures (minimal response) with ABM. Soft tissue findings showed no significant differences between treatments. CONCLUSIONS: These results suggest that the use of the P-15 synthetic cell-binding peptide combined with ABM yields better clinical results than the ABM alone in intrabony periodontal defects.

Histologic evaluation of periodontal healing in humans following regenerative therapy with enamel matrix derivative. A 10-case series.

BACKGROUND: Enamel matrix derivative (EMD) has been developed as a stimulus of periodontal regeneration. Human histology following its use has not been evaluated on pathologically altered root surfaces. METHODS: Ten intrabony defects in 8 patients were evaluated at 2 centers. Teeth with advanced adult periodontitis that were treatment planned for extraction were treated with sulcular incisions; full-thickness flap reflection; debridement of granulomatous tissue from the defect; placement of a notch in the root at the apical extent of calculus; mechanical root planing; conditioning with citric acid; application of EMD; wound closure with sutures; and placement of a periodontal dressing. Biweekly to monthly recalls were made until removal of small block section biopsies at about 6 months. The biopsies were fixed, decalcified, step-serial sectioned at 6 microns to 8 microns, and stained with hematoxylin and eosin or Masson's trichrome. RESULTS: Histologic evaluation of the region coronal to the base of the calculus notch showed evidence of regeneration (new cementum, new bone, and new periodontal ligament) in 3 specimens, new attachment (connective tissue attachment/adhesion only) in 3 specimens, and a long junctional epithelium in 4 specimens. No evidence of root resorption, ankylosis, or untoward inflammation was seen. CONCLUSIONS: The results of this study fulfill the proof of principle that use of EMD can result in periodontal regeneration on previously diseased root surfaces in humans, but on an inconsistent basis.

The effect of locally delivered controlled-release doxycycline or scaling and root planing on periodontal maintenance patients over 9 months.

BACKGROUND: This research report evaluates clinical changes resulting from local delivery of doxycycline hyclate (DH) or traditional scaling and root planing (SRP) in a group of patients undergoing supportive periodontal therapy (SPT). METHODS: In all, 141 patients received either DH (67) or SRP (74) treatment in sites > or =5 mm on one-half of their dentition at baseline and month 4. RESULTS: Clinical results were determined at month 9. Baseline mean probing depth recordings were similar between the two groups (DH = 5.9 mm; SRP = 5.9 mm). Mean month 9 results showed similar clinical results for attachment level gain (DH 0.7 mm; SRP 0.8 mm) and probing depth reduction (DH 1.3 mm; SRP 1.1 mm). Percentage of sites showing > or =2 mm attachment level gain at month 9 was 24.7% in the DH group and 21.2% in the SRP group. Thirty-nine percent (39%) of DH sites and 38% of SRP sites showed > or =2 mm probing depth reduction. When treated sides of the dentition were compared to untreated sides, DH showed a difference in disease activity (> or =2 mm attachment loss) from 19.3% (untreated) to 7.2% (treated); and SRP from 14.3% (untreated) to 8.1% (treated). CONCLUSIONS: Results show that both DH without concomitant mechanical instrumentation and SRP were equally effective as SPT in this patient group over the 9-month study period.

Bone and bone substitutes.

Bone replacement grafts will play a continuing role in periodontal and other regenerative therapy. Several choices are available to the clinician including autogenous, allogeneic, xenogeneic and a variety of alloplastic materials. Except for fresh autogenous bone, bone replacement graft(s) do not provide the cellular elements necessary for osteogenesis nor can they reliably be considered truly osteoinductive, but instead are mostly osteoconductive, providing a scaffold for bone deposition. Currently, significant decrease in clinical probing depth and gain of clinical attachment have been reported following use of bone replacement grafts when compared to flap debridement surgery alone for periodontal osseous defects. Reported differences among bone replacement grafts (autogenous, allogeneic, xenogeneic, and alloplastic) occur with respect to histological outcomes. Overall, probing depth reduction, attachment level gain and degree of defect fill are similar for all bone replacement grafts.

Improved efficacy of calculus removal in furcations using ultrasonic diamond-coated inserts.

Dentsply Cavitron Diamond Inserts provide improved efficacy in removing calculus from furcations. A total of 60 extracted human mandibular molar teeth had artificial calculus applied to the furcations, then were randomly treated with either sharp universal Gracey curettes (HAND), a plain ultrasonic TFI-10 tip in a cavitron instrument (CAV), or one of 2 diamond-coated cavitron instruments (TFI-10 fine-grit (FIN) and TFI-10 medium-grit (MED)) When the time needed to completely clean the furcations was evaluated, MED was the fastest, followed by FIN, CAV, and HAND, respectively. All of the powered instruments were faster than hand curettes with regard to effective in vitro calculus removal in furcations. The use of these types of instruments would reduce the time required to perform periodontal surgery and might improve regenerative therapy.

A 5-year follow-up of 16 patients treated with coralline calcium carbonate (BIOCORAL) bone replacement grafts in infrabony defects.

A resorbable coralline calcium carbonate graft material (BIOCORAL) (CalCarb) was evaluated as a bone replacement graft in human periodontal osseous defects. Following initial preparation and re-evaluation, flap surgery was carried out. Bone defects were curetted and root surfaces subjected to mechanical debridement and conditioning with tetracycline paste. The bone defects were grafted with CalCarb, and the host flaps replaced or slightly coronally positioned. Weekly, then monthly deplaquing was performed until surgical reentry at 6-12 months. Patients were then followed on approximate 3 month recalls for > or =5 years. Significant clinical changes included improvement in mean vertical clinical probing attachment level from 5.7 mm at surgery to 4.2 mm at re-entry to 4.0 mm at 5 years, decrease in mean probing pocket depth from 6.1 mm at surgery to 3.0 mm at re-entry to 3.3 mm at 5 years, and mean gingival recession from +0.4 mm at surgery to 1.0 mm at re-entry to 0.7 mm at 5 years (all at least p<0.05 from surgery to re-entry and surgery to 5 years, N.S. from reentry to 5 years via ANOVA). These favorable long-term results with CalCarb suggest that CalCarb may have a beneficial effect in the long-term clinical management of infrabony defects.

Bone replacement grafts. The bone substitutes.

Bone substitutes will play a pivotal role in the future of periodontal regeneration. They are synthetically derived or processed from exoskeletons of other species (xenograft) and are an alternative to autogenous or allogeneic bone replacement grafts. Bone substitutes do not provide the cellular elements necessary for osteogenesis, and they cannot be considered osteoinductive, but instead are osteoconductive, providing a scaffold for new bone deposition. Currently, significant decreases in clinical probing depth and attachment levels have been reported with bone substitutes when compared to flap debridement surgery alone for periodontal osseous defects. Reported differences among bone substitutes, autogenous grafts, and allograft materials, occur with respect to histologic outcomes. Overall, probing depth reduction and attachment level gains are similar for all bone replacement grafts.

Multi-center clinical evaluation of combination anorganic bovine-derived hydroxyapatite matrix (ABM)/cell binding peptide (P-15) as a bone replacement graft material in human periodontal osseous defects. 6-month results.

A synthetic cell-binding peptide (P-15) combined with anorganic bovine-derived hydroxyapatite bone matrix (ABM) was compared to demineralized freeze-dried bone allograft (DFDBA) and open flap debridement (DEBR) in human periodontal osseous defects in a controlled, monitored, multi-center trial. Following appropriate initial preparation procedures, flap surgery with defect and root debridement was performed. Three osseous defects per patient were treated randomly with one of three procedures after surgical preparation. Appropriate periodontal maintenance schedules were followed, and at 6 to 7 months re-entry flap surgery was performed for documentation and finalization of treatment. Analysis of variation (ANOVA) and t test analyses of patient mean values from 31 patients revealed that the combination ABM/P-15 grafts demonstrated significantly better mean defect fill of 2.8 +/- 1.2 mm (72.3%) versus a mean defect fill of 2.0 +/- 1.4 mm (51.4%) for defects treated with DFDBA (P <0.05) and a mean defect fill of 1.5 +/- 1.3 mm (40.3%) (P <0.05) for defects treated with DEBR. Other hard tissue findings showed similar clinically superior results with the use of ABM/P-15. Relative defect fill results showed 87% positive (50% to 100% defect fill) responses with ABM/P-15, 58% positive responses with DFDBA, and 41% positive responses with DEBR. There were 8 to 9 times more failures (minimal response) with DFDBA and DEBR (26% to 29% frequency) than with ABM/P-15. Soft tissue findings showed no significant differences among treatments except for greater clinical attachment level gain with ABM/P-15 compared to DEBR. These results suggest that the use of the P-15 synthetic cell-binding peptide combined with ABM yields better clinical results than either DFDBA or DEBR. Further studies are needed to determine the relative roles of the ABM and/or the P-15 in these improved results.

Six-year clinical evaluation of HTR synthetic bone grafts in human grade II molar furcations.

A biocompatible microporous composite of PMMA (poly-methyl-methacrylate), PHEMA (poly-hydroxy-ethyl-methacrylate) and calcium hydroxide bone replacement graft material (Bioplant HTR Synthetic Bone) was evaluated in 16 maxillary molar and 10 mandibular molar Grade II furcations in 13 patients. Following initial preparation, full thickness flaps were raised to gain access to the furcations; mechanical hand and ultrasonic root and defect debridement and chemical tetracycline root preparation were performed; furcation and adjacent osseous defects in each patient were grafted with HTR Synthetic Bone; and the host flaps replaced or slightly coronally positioned. Weekly, then monthly deplaquing was performed until surgical re-entry at 6-12 months. Patients were then followed on approximate 3-month recalls for > or = 6 yr. Evaluation of the primary clinical outcome of furcation grade change showed that in the maxilla 5/16 furcations were clinically closed, 9/16 were Grade I, and 2/16 remained Grade II; while in the mandible 3/10 were clinically closed, 5/10 were Grade I, and 2/10 remained Grade II. Other significant clinical changes included decrease in mean horizontal furcation probing attachment level from 4.4 mm at surgery to 2.2 mm at re-entry to 2.0 mm at 6 yr, decrease in probing pocket depth from 5.4 mm at surgery to 3.0 mm at re-entry to 3.2 mm at 6 yr, and improvement in vertical clinical probing attachment level from 5.4 mm at surgery to 4.2 mm at re-entry to 4.1 mm at 6 yr (all p < 0.05 from surgery to re-entry and surgery to 6 yr, n.s. from re-entry to 6 yr via ANOVA). These favorable results with HTR polymer are similar to several reports with other graft materials and with GTR barriers, and suggest that HTR polymer may have a beneficial effect in the clinical management of Grade II molar furcations.

Clinical evaluation of the speed and effectiveness of subgingival calculus removal on single-rooted teeth with diamond-coated ultrasonic tips.

Several studies have found incomplete calculus removal during periodontal treatment with traditional hand curets, sonic, and ultrasonic instruments. This study evaluated the speed and effectiveness of subgingival calculus removal with new diamond-coated ultrasonic tips on single-rooted teeth. Single session subgingival scaling and root planing was performed on 80 teeth with 5 to 12 mm probing depths in 15 patients. Each patient provided groups of 4 teeth that were randomly treated with either hand curets (HAND); standard smooth ultrasonic tip (US); or fine grit (FINDIAM) or medium grit (MEDDIAM) diamond-coated ultrasonic tips. The time taken to reach the therapeutic endpoint of a clean, smooth root surface in a defined region on each tooth with each instrument by the 3 therapists with differing experience levels was recorded. The teeth were then atraumatically extracted, stored in a surfactant, photographed at 10X, and the percent of calculus present in the area of the pocket or on a comparable control surface calculated by histometric point counting. ANOVA and paired t tests showed that mean percent remaining calculus on treated versus control surfaces was HAND 4.6 +/- 5.3 versus 57.5 +/- 28.2, US 4.7 +/- 6.4 versus 54.4 +/- 25.9, FINDIAM 4.3 +/- 5.2 versus 37.5 +/- 22.1, and MEDDIAM 3.4 +/- 4.2 versus 50.7 +/- 20.1, respectively (all P < 0.01). The mean time in seconds to reach the clinical endpoint ranged from HAND 289 +/- 193, US 194 +/- 67, FINDIAM 167 +/- 71, to MEDDIAM 147 +/- 92. All powered instruments were significantly faster than HAND (P < 0.05), but did not differ from each other. On a 0 = "smooth" to 3 = "rough" scale, most often HAND resulted in "smooth" surfaces (10/20), the powered tips of all types "slight" surface roughness (10/20 each), and US the most "moderate" roughness (7/20). There were no differences in percent calculus remaining, surface roughness, or time spent among the 3 treating clinicians despite their varying experience levels. The results of this study showed that percent calculus remaining was <5% with all the instruments given time ad libitum on a given root surface. Root roughness was generally slightly greater with all 3 powered tips. All of the powered instruments took significantly less time than the HAND. Both DIAM tips took less time than US. Diamond-coated ultrasonic tips appeared to be much more efficient than HAND or US in removing calculus in moderate-deep probing depths on single-rooted teeth in vivo.

Clinical regeneration with guided tissue barriers.

This review of the current periodontal literature evaluates clinical regeneration with guided tissue barriers in infrabony defects and furcations. A meta-analysis was conducted by calculating weighted means with confidence intervals for each treatment group. Clinical improvement in infrabony defects was best for polylactic acid/polyglactin (PLA/PGA) barriers, with a mean pocket reduction of 5.3 mm and a mean gain in clinical probing attachment level of 4.7 mm. For furcations, special attention was given to the frequency of either complete or partial (> or = 50%) furcation closure. Complete furcation closure was an infrequent result of guided tissue regeneration, occurring in only 7% to 19% of furcations treated with barriers. For the time period reported, the best clinical results in furcations and infrabony defects occurred with PLA/PGA-type barriers. However, there were no statistically significant differences among the various barriers in infrabony defects or furcations.

Root surface removal with diamond-coated ultrasonic instruments: an in vitro and SEM study.

Adequate root preparation in periodontal procedures includes the removal of plaque, calculus, and perhaps contaminated cementum and dentin. The purpose of this study was to evaluate and compare the amount of root surface removal and residual surface texture using similarly shaped regular (US) and both fine (FINDIAM) and medium (MEDDIAM) grit diamond-coated ultrasonic inserts. Forty-five (45) premolars extracted for orthodontic reasons were randomly divided into 3 groups of 15 teeth each. They were individually mounted in a jig and instrumented with a standardized 500 gram force while they were moved a precise horizontal distance of 12 mm over a 1.2 second period using specially designed and computer controlled instrumentation. Three measurements were made to the nearest 0.0005" at 3 points along the test area before instrumentation and after 10 and 20 strokes. The mean depth of root structure removed was US 5.8 +/- 6.6 microns, FINDIAM 50.1 +/- 14.2 microns, MEDDIAM 30.8 +/- 12.1 microns, after 10 strokes, and US 12.7 +/- 10.9 microns, FINDIAM 83.3 +/- 20.1 microns, MEDDIAM 58.7 +/- 17.9 microns after 20 strokes, respectively. All 3 instruments were different from each other (P < 0.001) in the 10 stroke group, while in the 20 stroke group FINDIAM and MEDDIAM were different from US (P < 0.001), but not from each other. Only FINDIAM showed a significant difference between 10 and 20 stroke values for depth of root removal. Modified loss of tooth substance index SEM scores indicated increasingly greater root surface roughness from US to FINDIAM to MEDDIAM. Substantially greater root surface removal and greater residual root surface roughness occurred with diamond-coated ultrasonic inserts under standardized in vitro conditions. These results suggest that caution should be used with diamond-coated ultrasonic instruments during periodontal root planing procedures.

Multi-center evaluation of bioabsorbable collagen membrane for guided tissue regeneration in human Class II furcations.

Clinical data related to GTR therapy for Class II furcations were analyzed from 7 treatment centers that evaluated one of two possible treatment pairs, either bioabsorbable collagen membrane (Type I bovine tendon collagen) (COLL) versus control surgical debridement (DEBR) or COLL versus expanded polytetrafluoroethylene (ePTFE). After initial preparation and re-evaluation, full thickness flaps were reflected, the defects debrided, and the roots planed. Furcations and associated bony defects in each patient were randomly assigned to one of the 2 treatments in each pair, and the flaps closed. Patients received quarterly periodontal maintenance until surgical re-entry at 6 to 12 (mean 11.1) months. Data from 59 pairs of Class II furcations were analyzed via paired t, Wilcoxon signed rank, and RM ANOVA tests. COLL showed better results than DEBR for vertical defect fill, percent defect resolution, and horizontal furcation fill. When COLL was compared to ePTFE in furcations across patients, no differences were found. Both COLL and ePTFE resulted in an improvement in clinical furcation Class about 50% of the time (compared to 7% frequency with DEBR). COLL use yielded 8 and ePTFE yielded 1 clinically-complete furcation closures. COLL barriers resulted in generally favorable clinical results in furcation defects, appeared to be better than DEBR alone, and were at least similar to and often better than ePTFE. COLL of the type used in this study appears to be a useful and beneficial material for regenerative therapy in Class II furcation type periodontal defects.

Evaluation of the surface integrity of hydroxyapatite-coated threaded dental implants after insertion.

The surface characteristics and changes of hydroxyapatite-coated threaded dental implants after insertion into bone (veal calf ribs) with similar cortical and medullary characteristics to the human maxilla and posterior mandible (type III or IV bone) were studied. Hydroxyapatite-coated threaded implants from six vendors were coded A, B, C, D, E, and F. Four implants from each vendor were subjected to conventional placement following the manufacturer's instructions, placement without tapping of the osteotomy site, or evaluated as controls. The implants were recovered atraumatically and examined by scanning electron microscopy at x 35 and x 100 magnification. Photomicrographs were examined and graded by two independent examiners. Statistically significant differences were found using Kruskal-Wallis ANOVA and Wilcoxon Signed Ranks tests in surface integrity between conventional and nontapped treatment for groups C and D; between conventional placement and controls for groups A, B, and F; between nontapped placement and controls for groups A, B, C, D, and E; and among the manufacturers with respect to conventional placement for groups A, B, and E as compared with the other groups (P < 0.05). These findings suggest that surface changes of hydroxyapatite-coated threaded implants may occur during placement, particularly in undersized and untapped osteotomy sites. The changes could result in differences in integration and performance of some implant systems.