HISTOLOGICAL-FINDINGS IN GUIDED BONE REGENERATION (GBR) AROUND TITANIUM DENTAL IMPLANTS WITH AUTOGENOUS BONE CHIPS USING A NEW RESORBABLE MEMBRANE

The aim of this study was to test the value of the new polydioxanone-m embrane (PDS(R), Ethicon, Norderstedt, Germany) in combination with au togenous bone as a spacer for guided bone regeneration of denuded impl ant surfaces compared to simple augmentation. Forty implants were sele cted for 20 test cases (with membrane) and 20 control cases (without m embrane) and were distributed randomly in 19 patients who were treated according to a standard protocol and examined. The defects were fille d with autogenous bonechips, harvested interforaminally or locally, an d were covered by the PDS membrane within the test group (control grou p: periosteum). The membranes were fixed with Memfix((R)) screws and c overscrews. Seven membranes became exposed and were removed before ree ntry. Within the control group, three augments were sequestered. After 6 months, reentry was performed, the healing results were observed cl inically and biopsies were taken. The test group, including the seven cases with early removal of the membrane, showed that bone had filled in the defects in 95% of test cases, compared with 60% for the control group. The results of this study show that single augmentation of def ects exceeding 9 mm(2) is not sufficient. The membrane used in this in vestigation may be helpful for guided bone regeneration (GBR) at denud ed screw thread sites in implant dentistry.