Randomized controlled clinical study assessing two membranes for guided bone regeneration of peri-implant bone defects: 3-year results

ObjectivesTo assess two- and three-dimensional changes of the peri-implant tissues as well as clinical, biological, and radiological outcomes of implants having been treated with resorbable or nonresorbable membranes at 3years. Materials and methodsTwenty-three patients were re-examined after having received a single-tooth implant in the esthetic zone in conjunction with guided bone regeneration (GBR) using either a resorbable (RES) or a titanium-reinforced nonresorbable membrane (N-RES) and demineralized bovine bone mineral. Volumetric and linear as well as clinical and radiographic measurements were performed at crown insertion (baseline), at 1year (FU-1) and 3years (FU-3). Statistics were performed by means of parametric and nonparametric tests. ResultsMinor, but ongoing buccal volume loss was observed in both groups during the 3-year follow-up. A slightly higher volume loss was observed in group RES (-0.22mm) compared to N-RES (-0.14mm) at 1year (FU-1), but aligned at 3years (FU-3) RES (-0.30mm) N-RES (-0.32mm). All changes over time were statistically significantly different within (p<.05), but not between the groups (p>.05). Stable median interproximal bone levels after 3years (FU-3); 0.26mm (0.04; 0.36) (RES) and 0.14mm (0.08; 0.20) (N-RES) and healthy tissues (BOP, PD) were obtained with both membranes. ConclusionsBoth treatment modalities resulted in minor, but ongoing contour changes of the peri-implant tissues. Stable interproximal bone levels and healthy tissues can be obtained with membranes up to 3years.