Treatment of intraosseous defects with bioabsorbable barriers alone or in combination with decalcified freeze-dried bone allograft: a randomized clinical trial.

BACKGROUND: This study clinically compares the outcomes obtained from the use of a bioabsorbable barrier device in combination with demineralized freeze-dried bone allograft (DFDBA) to the results obtained from the barrier device used alone in the treatment of human intraosseous defects. METHODS: The study consisted of 30 patients with one intraosseous periodontal defect each. The trial included defects with loss of attachment of > or = 6 mm, with a radiographically detectable defect of at least 4 mm and with at least 2 remaining osseous walls. After the hygienic phase, at baseline, probing depth (PD), clinical attachment level (CAL), and recession (REC) were measured. During open flap debridement, the defects were randomly assigned to receive either a polylactic acid (PLA) barrier in combination with DFDBA (test) or a PLA barrier alone (control). Additionally, baseline osseous intrasurgical measurements of the periodontal defect were obtained to evaluate the amount of bone regeneration. PD, CAL, and REC were remeasured at 6 and 12 months postsurgery and osseous measurements repeated at 12 months during a re-entry procedure. RESULTS: Two-sample t-test comparisons of mean PD, CAL, and REC measurements (mm) between test (PLA+DFDBA) and control (PLA alone) groups at baseline, PLA+DFDBA: PD = 7.3, CAL = 8.1, REC = -0.7; PLA-alone: PD = 7.9, CAL = 8.4, REC = -0.5, were not statistically different (P>0.05). The following mean changes (delta) at 6 months for the test and the control groups were: decreased PD = 3.6 and 4.0 mm; gain CAL = 2.7 and 3.1 mm; and increased REC = -0.8 and -0.8 mm, respectively. At 12 months the changes for the test and control groups were: decreased PD = 3.3 and 4.1 mm; gain CAL = 2.3 and 3.2 mm; and increased REC = -0.8 and -1.0 mm, respectively. Two-sample t-test comparisons between PD, CAL, and REC changes yielded no significant differences between treatments (P > 0.05), except for the change in CAL at 12 months in favor of the control group, P = 0.008. Comparisons of osseous measurements resulted in no significant differences between groups at baseline and at 12 months (P > 0.05). The intrabony defect filled on the average 3.72 mm for the test and 4.85 mm for the control group. The experimental defects showed a 4.73 mm defect depth reduction, while the control defects reduced 5.35 mm. Re-entry measurements of osseous crest resorption were 1.1 mm for the test and 0.61 mm for the control. CONCLUSIONS: In the intraosseous defects treated in this study, the addition of DFDBA to the GTR procedure did not significantly enhance the clinical results obtained with the GTR procedure alone.

Comparison of bioabsorbable and bioinert membranes for guided bone regeneration around non-submerged implants. An experimental study in the mongrel dog.

The aim of this clinical investigation was to evaluate the effect of guided bone regeneration around non-submerged implants using different barrier membranes. Five adult mongrel dogs were used in this investigation. After having all premolars extracted and implant osteotomies performed in the regions of the former premolars, buccal bone defects were created. Subsequently, 3 implants were placed and the defects treated with 1 of the following 3 modalities: a) guided bone regeneration using an expanded polytetrafluoroethylene membrane, b) guided bone regeneration using a bioabsorbable membrane made from a synthetic copolymer of glycolide and lactide and c) no membrane application. Following implant and membrane placement, the mucoperiosteal flaps were repositioned and tightly sutured around the neck of the implants allowing for a non-submerged healing. After a healing period of 6 months, the animals were sacrificed and the specimens processed for histologic evaluation. The clinical pre-treatment defects between the different treatment groups were not statistically different (bioinert membrane group: 4.9 mm; control group: 4.8 mm; bioabsorbable membrane group: 4.5 mm). The remaining histological defects after 6 months of healing amounted to approximately 2.5 mm in the bioinert membrane group, 5.7 mm in the control group and 6.0 mm in the bioabsorbable membrane group. A significant difference was observed between the bioinert membrane group and the other 2 groups. The mineralized bone-to-implant contact in the bioinert membrane group was 51.5%, in the control group 46.3% and in the bioabsorbable membrane group 37.5%. The values between the bioinert membrane group and the bioabsorbable membrane group were statistically different. The results of this study indicate that bone regeneration with bioinert e-PTFE membranes around non-submerged implants is possible. The utilized absorbable polyglycolic/polylactid membrane did not show any bone regenerative effect and the results did not differ from the control group without membrane application.

The effects of guided bone regeneration and grafting on implants placed into immediate extraction sockets. An experimental study in dogs.

Guided bone regeneration (gbr) for the treatment of insufficient bone volume around implants can be performed using membranes with or without grafting materials (i.e., autogenous, allogenous, xenogenous, or alloplastic grafts). A possible way to evaluate the quality of implant osseointegration is the torque necessary to remove implants from their bony housing. The aim of this study was to compare the torques necessary to remove dental implants from implant beds reconstructed with different bone substitutes and GBR or GBR alone in 6 adult mongrel dogs. All mandibular premolars were extracted and 3 extraction sockets on each side were enlarged using a trephine bur. A 13 mm titanium screw-type dental implant (3.75 mm diameter) was placed in each enlarged extraction socket so that only the apical 3 to 4 mm were engaged in bone. The 3 defects were then randomly treated with either 1) canine demineralized freeze-dried bone allograft (DFDBA) plus GBR using an expanded polytetrafluoroethylene membrane (DFDBA+GTAM); 2) bioabsorbable hydroxyapatite and GBR (HA+GTAM); or 3) GBR (GTAM alone). After 6 months, the torque to remove the implants was measured in 4 animals and analyzed using ANOVA. There were no statistically significant differences between the 3 groups (GTAM alone: 46.37+/-16.41 Ncm; HA+GTAM: 46.00+/-16.59 Ncm; DFDBA+ GTAM: 52.15+/-29.24 Ncm). In addition, the influence of early removal of barriers on the torque values was evaluated with the t-test. Comparing exposed versus retained membranes by treatment modality, the only statistically significant difference was found in the DFDBA+GTAM group. When the torque values of all implants with exposed and retrieved membranes were compared to all those with retained membranes a significant difference could be detected. Histologic sections were prepared from the 2 dogs not included in the removal torque testing. In the histometric analysis the GTAM alone group showed a mean mineralized bone-to-implant-contact of 27.1%, the DFDBA+GTAM group of 34.6%, and the HA+GTAM of 39.3%. The mineralized bone-to-implant-contact of the HA+GTAM group was significantly higher than that of the GTAM alone group. In addition, the mineralized bone-to-implant-contact was divided into an apical and coronal part using the apical seventh thread as the dividing landmark. In the apical region, there was no significant difference between the groups regarding mineralized bone-to-implant-contact. In the coronal part the mineralized bone-to-implant-contact of the GTAM alone group was significantly lower compared to the other 2 groups. Within the limits of this investigation, it can be concluded that the type of grafting material will not influence torque removal values, but that early membrane exposure and removal will negatively influence the torque measurements. The combination of GBR with a bone substitute increased the mineralized bone-to-implant contact.

Effects of expanded polytetrafluoroethylene and polylactic acid barriers on healthy sites.

The configuration of the barrier devices to treat interproximal defects by guided tissue regeneration (GTR) necessitates inclusion of healthy adjacent teeth to secure the barriers in place. The purpose of this study was to evaluate the effects of expanded polytetrafluoroethylene (ePTFE) and polylactic acid (PLA) barrier devices on probing depth (PD), clinical attachment level (CAL), and crestal bone height in healthy sites. The study included 30 patients who were in an earlier study which compared the effects of GTR utilizing an ePTFE or a PLA barrier in intrabony defects. Thirty defects were randomly assigned to receive either a PLA (test) or an ePTFE barrier (control) after open flap debridement. The sites in this investigation included those healthy sites in the immediately adjacent non-affected teeth covered by the barriers. CAL and PD were measured at baseline and 12 months. Intrasurgical crestal bone height was recorded at the time of barrier placement and at a 12-month re-entry. Two-sample t-test comparisons of PD and CAL measurements between barrier device covered sites at baseline (PD: ePTFE, 2.32+/-0.51; PLA, 2.59+/-0.74; CAL: ePTFE, 2.71+/-0.66; PLA, 2.59+/-0.65 mm), and at one year (PD: ePTFE, 2.14+/-0.37; PLA, 2.07+/-0.56; CAL: ePTFE, 3.14+/-1.05; PLA, 2.75+/-0.73 mm) were not statistically different (P > 0.05). Paired t-test was utilized to compare changes in PD, CAL, and crestal bone height from baseline to 12 months. A statistically significant reduction in PD was found in the PLA group (delta = -0.52, P = 0.01) while no significant change was found in the ePTFE group (delta = -0.18, P = 0.18). Change in CAL was statistically significant in the ePTFE group (delta = 0.43, P = 0.02) while no significant change was found in the PLA group (delta = 0.16, P = 0.39). Crestal bone height changes from baseline to 12 months were statistically different for both groups (ePTFE, delta = 0.8 mm, P = 0.001; PLA, delta = 0.6 mm, P = 0.001). These resorptive changes, when compared between treatment groups were not statistically different (P > 0.05). In conclusion, the placement of ePTFE or PLA barriers on healthy sites resulted in probing depth reductions and loss of attachment of 0.5 mm or less. Additionally, both groups exhibited less than 1.0 mm of crestal bone resorption.

Assessment of guided tissue regeneration procedures in intrabony defects with bioabsorbable and non-resorbable barriers.

THE PURPOSE OF THIS STUDY was to assess periodontal regenerative techniques in intrabony defects utilizing a bioabsorbable, polylactic acid (PLA) barrier or the non-resorbable, expanded polytetrafluoroethylene (ePTFE) barrier. Thirty patients (26 to 64 years old) each with one radiographically evident intrabony periodontal lesion of probing depth > or = 6 mm participated in a 12-month controlled clinical trial. The subjects were randomly divided into two independent groups. The test group (n = 16) received a PLA barrier. The control group (n = 14) received an ePTFE barrier. Plaque index (PI), gingival index (GI), probing depth (PD), clinical attachment level (CAL), and bone fill were recorded by a single calibrated examiner not involved with the surgical treatment prior to surgery, and at 6, 9, and 12 months postsurgery. The treatment results were statistically analyzed utilizing two sets of data. The "averaged-site" data set consisted of values computed from the averaging of measurements from all sites encompassing the defect. The second data set was comprised of only the deepest measurement of the defect. Statistical tests used to analyze these data sets included the t-test and paired t-test for parametric data and the Wilcoxon rank sum test and the Wilcoxon signed rank test for non-parametric data. Analyses with both the averaged-site data and deepest-site data resulted in significant improvements in PD reductions, CAL, and bone fill, after 12 months of healing with both the PLA and ePTFE barrier devices. Comparisons of healing response between treatments found no significant differences when the averaged-site data were analyzed. When only the deepest site of the defect was considered, the control group resulted in significantly more attachment gain (ePTFE, 3.36 mm; PLA, 1.75 mm; P < 0.02) and shallower probing depths (ePTFE, 3.29 mm; PLA, 4.69 mm; P < 0.01) than the test group. In intrabony defects, the use of PLA or ePTFE barriers in GTR procedures yielded comparable clinical results; however, in this study, data analysis using the deepest site of the defect found, after 12 months of healing, significantly more attachment gain and shallower probing depths with ePTFE.

Guided tissue regeneration. A status report for the American Journal of Dentistry.

This report reviews clinical results which have been obtained with guided tissue regeneration (GTR) using non-resorbable and resorbable materials. The report highlights the clinical factors that affect and that should be considered in order to improve the predictability of the results obtained after GTR. The indications for GTR procedures are reviewed and the surgical technique is described. The importance of periodontal maintenance, and the significance of adjunctive therapies in GTR procedures are also discussed. Based upon the vast scientific information and clinical experience with GTR, it can be stated that with the use of either resorbable or non-resorbable materials a new attachment, determined both clinically and histologically, will be promoted providing that the principles of GTR are properly implemented.

Treatment of a patient with hereditary gingival fibromatosis: a case report.

A case of hereditary gingival fibromatosis is presented. Treatment consisted of apically positioned flap surgery and CO2 laser evaporation. Diagnostic and treatment issues are discussed.

The diagnosis and treatment of discoid lupus erythematosus with oral manifestations only: a case report.

A case of discoid lupus erythematosus with oral manifestations only is presented. The patient complained of painful palatal ulcers that limited her dietary intake. A topical therapeutic regimen using plastic carriers containing clobetasol propionate was beneficial in significantly relieving the oral discomfort. The clinical and microscopic differential diagnoses for this mucocutaneous disease are also discussed.