Combined use of xenogeneic bone substitute material covered with a native bilayer collagen membrane for alveolar ridge preservation: A randomized controlled clinical trial

AIM: The aim of this split-mouth randomized controlled study was to evaluate radiographic dimensional changes after tooth extraction in posterior sites treated with a ridge preservation technique or left for spontaneous healing. MATERIALS AND METHODS: In a total of 18 patients, tooth extraction in posterior sites of the upper and lower jaw was performed in a split-mouth design. The post-extraction sockets were randomly assigned to the following two treatment modalities: deproteinized bovine bone mineral (DBBM) with 10% collagen (DBBM-C) covered with a native bilayer collagen membrane (NBCM) (test group) and spontaneous healing (control group). Cone beam computed tomography (CBCT) scans were performed after extractions, 3 and 6 months later. The following parameters were measured: the height of the buccal bone plate (BH), height of the palatal bone plate (PH), horizontal width of the extraction socket at 1 mm, 3 mm, and 5 mm (HW-1, HW-3, HW-5), and the horizontal width (thickness) of the buccal bone plate at 1 mm, 3 mm, and 5 mm (BHP-1, BHP-3, BHP-5). Statistical analysis was performed applying a nonparametric Wilcoxon signed-rank test. RESULTS: The CBCT analysis showed a bone loss compared to baseline in test and control group. The measurements which have reached statistically significant differences at 6 months were BH (test: -2.31% vs control: -13.11%), PH (test: -2.07% vs control: -15.32%), HW-1 (test: -17.14% vs control: -32.47%), and HW-3 (test: -11.65% vs control: -28.47%). CONCLUSIONS: The posterior ridge preservation technique using DBBM-C covered with a NBCM is a valid approach reducing the amount of the radiographic loss in alveolar ridge dimensions.