Effect of liquid protein diet on collagen metabolism of the gingiva of young rats.

The effects of liquid protein diet (LPD) on gingival collagen metabolism were evaluated in young rats. Experimental animals received a LPD, while pair-fed and ad libitum groups received a 20% casein diet. Prior to sacrifice at days 23, 35 and 48 post-partum, animals from each group were injected with C14-proline. Gingival tissues from the palate were excised and analyzed for collagen content and collagen synthesis. Results of body-weight changes at day 48 showed a 20% decrease in the LPD group, while pair-fed and ad libitum groups increased 47% and 267%, respectively. Collagen content per gram of gingiva was not significantly different among the three groups. Gingival collagen synthesis, however, did show significant differences among the three groups. It was concluded that while LPD effects on the overall body condition were profound, LPD exerts minimal effect on gingival collagen metabolism in young rats.

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.

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.

Effect of various graft materials with tetracycline in localized juvenile periodontitis.

Ten patients with bilateral, posterior osseous defects associated with localized juvenile periodontitis (LJP) completed the study. Following the initial therapy, osseous defects were surgically debrided and grafted with a 4:1 volume ratio combination of either Synthograft/tetracycline (b-TCP/TTC), Periograf/tetracycline (HA/TTC) or freeze-dried bone allograft/tetracycline (FDBA/TTC). Graft materials were selected randomly for each half mouth following defect debridement, with a different material used on the opposite side for that patient. Immediately following each surgery, patients were placed on doxycycline 100 mg/day for 10 days. Direct re-entry evaluation of 51 osseous defects demonstrated no significant differences among the graft materials regarding hard tissue or soft tissue changes, except for greater percent defect fill for HA/TTC compared to b-TCP/TTC. Significant decreases in defect depth and pocket depth were achieved with each graft material. No adverse reactions to the use of any of the graft materials in combination with local and systemic tetracycline were found. The results indicate all three graft materials used in conjunction with TTC are acceptable and beneficial for the treatment and repair of osseous defects associated with localized juvenile periodontitis.

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.

Evaluation of durapatite ceramic as an alloplastic implant in periodontal osseous defects. II. Twelve month reentry results.

Thirteen patients received Durapatite, a hydroxylapatite ceramic (Periograf), as a bone implant material in various types of intrabony defects following internally beveled full thickness flaps, root planing, and defect debridement. All osseous margins and defects were measured from the cemento-enamel junction (CEJ) at specific locations using a standardized periodontal probe. Similarly debrided, nonimplanted defects served as controls. Defect selection as either experimental or control site was based on an alternating defects design after local therapy was completed. Periodontal dressing and systemic tetracycline were used for 10 days. Postsurgical visits for documentation and plaque control were at 10, 20 and 30 days, and 3, 6, 9 and 12 months. Measurements relating to defect changes were made at the 12-month surgical reentry. For evaluation purposes original defect depths were divided into three groups. In Group I (less than 3 mm) defect fill was 1.0 mm (47%) for the implanted defects and 0.3 mm (33%) for the control sites (significantly different at P less than 0.05). In Group II (3-6 mm) defect fill of 1.7 mm (44%) for implanted sites was significantly better (P less than 0.05) than the 0.8 mm (29%) found in control sites. In the deepest group (Group III, greater than 6 mm) Durapatite placement yielded 2.1 mm (32%) of defect fill while debridement alone resulted in 1.8 mm (26%) of fill (P greater than 0.05). Hard tissue responses demonstrated a substantial advantage for use of Durapatite over controls, while soft tissue changes were similar for both.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

Two multi-center studies evaluating locally delivered doxycycline hyclate, placebo control, oral hygiene, and scaling and root planing in the treatment of periodontitis.

BACKGROUND: The clinical efficacy and safety of doxycycline hyclate (8.5% w/w) delivered subgingivally in a biodegradable polymer (DH) was compared to placebo control (VC), oral hygiene (OH), and scaling and root planing (SRP) in 2 multi-center studies. METHODS: Each study entered 411 patients who demonstrated moderate to severe periodontitis. Patients had 2 or more quadrants each with a minimum of 4 qualifying pockets > or =5 mm that bled on probing. At least 2 of the pockets were > or =7 mm. Treatment with DH, VC, OH, or SRP was provided at baseline and again at month 4. Clinical parameters were recorded monthly. RESULTS: DH and SRP resulted in nearly identical clinical changes over time in both studies. Mean 9 month clinical attachment level gain (ALG) was 0.8 mm for the DH group and 0.7 mm for the SRP group in Study 1, and 0.8 mm (DH) and 0.9 mm (SRP) in Study 2. Mean probing depth (PD) reduction was 1.1 mm for the DH group and 0.9 mm for the SRP group in Study 1 and 1.3 mm for both groups in Study 2. Frequency distributions showed an ALG > or =2 mm in 29% of DH sites versus 27% of SRP sites in Study 1 and 31% of DH sites versus 34% of SRP sites in Study 2. PD reductions > or =2 mm were seen in 32% of DH sites versus 31% of SRP sites in Study 1 and 41% of DH sites versus 43% of SRP sites in Study 2. Comparisons between DH, VC, and OH treatment groups showed DH treatment to be statistically superior to VC and OH. Safety data demonstrated a benign safety profile with use of the DH product. CONCLUSIONS: Results of this trial demonstrate that treatment of periodontitis with subgingivally delivered doxycycline in a biodegradable polymer is equally effective as scaling and root planing and superior in effect to placebo control and oral hygiene in reducing the clinical signs of adult periodontitis over a 9-month period. This represents positive changes resulting from the use of subgingivally applied doxycycline as scaling and root planing was not limited regarding time of the procedure or use of local anesthesia.

Effects of the Nd:YAG dental laser on plasma-sprayed and hydroxyapatite-coated titanium dental implants: surface alteration and attempted sterilization.

The Nd:YAG dental laser has been recommended for a number of applications, including the decontamination or sterilization of surfaces of dental implants that are diseased or failing. The effects of laser irradiation in vitro (1) on the surface properties of plasma-sprayed titanium and plasma-sprayed hydroxyapatite-coated titanium dental implants, and (2) on the potential to sterilize those surfaces after contamination with spores of Bacillus subtilis have been examined. Surface effects were examined by scanning electron microscopy, energy dispersive spectroscopy, and x-ray diffraction after laser irradiation at 0.3, 2.0, and 3.0 W using either contact or noncontact handpieces. Controls received no laser irradiation. Melting, loss of porosity, and other surface alterations were observed on both types of implants, even with the lowest power setting. For the sterilization study, both types of implants were first sterilized by exposure to ethylene oxide and then contaminated with spores of B subtilis. After laser irradiation, the implants were transferred to sterile growth medium and incubated. Laser irradiation did not sterilize either type of implant. The spore-contaminated implants in the control group were successfully sterilized with ethylene oxide.

Loaded and nonloaded titanium versus hydroxyapatite-coated threaded implants in the canine mandible.

A commercially pure titanium threaded implant was compared to a hydroxyapatite-coated threaded implant of similar geometric design and dimensions in the canine model. Bilateral posterior implants supported fixed prostheses, and some implants in the same mandibles served as unloaded control implants. Implants were evaluated clinically, radiographically, and histomorphometrically at the light microscope level to detect any differences in bone response to loaded conditions. No statistically significant differences were found between the two implant designs under loaded or nonloaded conditions with regard to mobility, probing depth, percentage of osseointegration, and crestal bone position.

Frequency of furcation closure with regenerative periodontal therapy.

A review of the literature was performed related to the frequency of closure of Grade II furcations with various regenerative therapies such as bone replacement grafts (BRG), coronally positioned flaps (CPF), guided tissue regeneration barriers (GTR), or open flap debridement (OFD). Fifty papers involving 1,016 furcations were evaluated. Complete furcation closure was reported only 20% of the time. Clinical change from Grade II to Grade I (partial furcation fill) was found in an additional 33% of the cases. Therefore, general improvement in clinical furcation status has been reported only about 50% of the time. The most effective furcation regenerative therapy was the combination of GTR plus BRG (91% overall positive). Similar overall positive results (88%) were achieved with nondemineralized allogeneic freeze-dried bone plus tetracycline without a barrier. The least effective therapy for regeneration in furcations was OFD (2% complete furcation closures and 13% partial furcation closures). If complete furcation closure is a primary goal of regenerative therapy, that goal would not appear to be commonly met.

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.