Comparison of two different surgical approaches to increase peri-implant mucosa thickness: A randomized controlled clinical trial

BACKGROUND: Current evidence supports the positive effect of adequate peri-implant mucosal thickness (PMT) on both marginal bone level stability and esthetic outcomes. While the subepithelial connective tissue graft (sCTG) has been traditionally considered as the gold standard for peri-implant mucosal augmentation, acellular dermal matrix (ADM) may be a valid alternative. The primary aim of this randomized clinical trial was to determine the clinical efficacy of ADM in the augmentation of PMT as compared to an autologous sCTG. METHODS: Patients who could benefit from peri-implant mucosal augmentation at the time of implant placement were recruited. Participants were randomized to the control (simultaneous sCTG) or test (simultaneous ADM) group. The primary outcome in this study was changes in PMT between baseline and 16 weeks later. Keratinized mucosal width (KMW) changes, modified wound healing index (MWHI) variations and patient-reported outcome measures (PROMs) were recorded, as well. RESULTS: A total of 20 participants were recruited per an a priori power analysis. There were no statistically significant differences between groups at baseline for any of the parameters analyzed. The gain in PMT at 1 mm, 3 mm, and 5 mm from the expected mucosal margin was 0.44 ± 2.04 mm, 1.20 ± 1.48 mm, and 1.20 ± 0.89 mm in the sCTG group, and 0.05 ± 1.57 mm, 0.85 ± 1.29 mm, and 1.45 ± 1.17 mm in the ADM group. No statistically significant differences in terms of PMT, KMW, and MWHI changes were observed between groups. The perceived discomfort was higher at 2 and 4 weeks for patients in the sCTG group. CONCLUSION: ADM produces similar outcomes to sCTG in terms of mucosal augmentation at the time of implant placement.