A randomized controlled clinical trial evaluating efficacy and adverse events of different types of recombinant human bone morphogenetic protein-2 delivery systems for alveolar ridge preservation

Objectives This 12-week clinical trial evaluated efficacy and adverse events for two recombinant human bone morphogenetic protein-2 (rhBMP-2) delivery systems in alveolar ridge preservation. Materials and methods Sixty-four patients had a single tooth that required replacement with an implant, surrounded by > 50% alveolar bone height. Two cohorts (n = 32 patients each) were randomized to receive a rhBMP-2-soaked absorbable collagen sponge (test group), or beta-tricalcium phosphate and hydroxyapatite particles (control group) immersed in rhBMP-2, at the implant site. Bone height and width changes at 25%, 50%, and 75% of extraction socket level (ESL) were compared. Adverse events were assessed in the same period. In addition to the randomized controlled clinical trial, histological analysis of 21 patients (test group [n = 12], control group [n = 9]) was conducted, 4 months after alveolar ridge preservation. A non-inferiority test was used to analyze changes in alveolar bone height between groups (p = 0.05). A Wilcoxon rank-sum test was used to analyze changes in alveolar bone width and histomorphometric results between groups (p = 0.05). Results All patients showed good healing without severe adverse events. The lower limit of the one-sided 97.5% confidence interval in the difference between the two groups was 0.0033 (non-inferiority margin: -0.185); thus, the test group showed non-inferiority to the control group. Wilcoxon rank-sum test analysis did not show statistically significant differences between groups with regard to changes in alveolar bone width and histomorphometric analysis. Conclusions The delivery systems showed similar efficacy for alveolar ridge preservation without severe adverse events.