TREATMENT OF PERI-IMPLANT DEFECTS WITH GUIDED BONE REGENERATION - A COMPARATIVE CLINICAL-STUDY WITH VARIOUS MEMBRANES AND BONE-GRAFTS

In this clinical study, a bioabsorbable membrane (Biofix) and two augm entation membranes made of expanded polytetrafluoroethylene (Gore-Tex) were tested for their osteopromotive potential. Forty-six implants we re augmented with Gore-Tex membranes, 45 implants with titanium-reinfo rced Gore-Tex membranes, and 38 periimplant defects with a resorbable polyglycolid membrane (Biofix). Autogenous bone (n = 85) and bovine bo ne matrix (Bio-Oss, n = 16) were used as filling materials beneath mem branes. The results showed that bone repair is significantly improved by the use of membrane techniques. The average rate of bone regenerati on with nonresorbable membranes was 84% (GTAM) and 81% (TR-GTAM). The use of Biofix membranes resulted in an average bone gain of 60%. The d ifferences in efficacy established for the three types of membranes we re found to be statistically significant (P < .001). Barrier membranes represent a valid technique for the treatment of periimplant defects. Clinical and histologic results showed that Bio-Oss is an osteoconduc tive scaffold that promotes new bone formation.