Randomized clinical study assessing two membranes for guided bone regeneration of peri-implant bone defects: clinical and histological outcomes at 6months

PurposeTo test whether or not one of two membranes is superior for peri-implant-guided bone regeneration in terms of clinical and histologic outcomes. Material and methodsIn 27 patients, 27 two-piece dental implants were placed in single-tooth gaps in the esthetic area. Buccal dehiscence and/or fenestration-type defects were regenerated using demineralized bovine bone mineral and randomly covered with either a resorbable membrane (RES) or a titanium-reinforced non-resorbable membrane (N-RES). Clinical measurements included vertical defect resolution and the horizontal thickness of regenerated bone at implant placement and at 6months. Statistics were performed by means of nonparametric testing. ResultsThe remaining mean vertical defect measured 4mm (2.07) (RES) and 2.36mm (+/- 2.09) (N-RES) (P=0.044) at baseline and 0.77mm (+/- 0.85) (RES) and 0.21mm (+/- 0.80) (N-RES) (P=0.021) at re-entry. This translated into a defect resolution of 85% (RES) and 90.7% (N-RES) (P=0.10). The horizontal thickness after augmentation measured 3.46mm (+/- 0.52) (RES) and 2.82mm (+/- 0.50) (N-RES) (P=0.004). The mean loss in horizontal thickness from baseline to re-entry measured 2.23mm (SD +/- 1.21) (RES) and 0.14mm (+/- 0.79) (N-RES) (P=0.017). The horizontal changes in thickness at the implant shoulder level were statistically significant between the groups (P=0.0001). ConclusionsBoth treatment modalities were clinically effective in regenerating bone as demonstrated by a similar horizontal thickness and vertical defect fill at 6months. The N-RES group exhibited significantly less horizontal bone thickness reduction from baseline to follow-up.