Peri-implant tissue changes at sites treated with alveolar ridge preservation in the aesthetic zone: Twenty-two months follow-up of a randomized clinical trial

Aim To compare tissue changes at implant sites previously treated with two biomaterials for alveolar ridge preservation (ARP) in the aesthetic zone, 1 year after restoration. Materials and methods Sixty-six participants were treated with ARP using demineralized bovine bone mineral (DBBM) or DBBM +10% of collagen (DBBM-C), both covered with a collagen matrix (CM). Dental implants were placed, and definitive crowns were installed. Silicon impressions were taken before tooth extraction (T0), 2 weeks after crown insertion (T1) and 1 year after restoration (T2). Mid-facial mucosal level change (MLC), soft tissue thickness changes (TT), and marginal bone loss (MBL) were analysed using inter-group comparisons. Results Fifty-four participants were included in the analysis. The mid-facial level change between T0-T1 and T1-T2 showed no statistical difference between DBBM and DBBM-C. Between T0 and T1 for soft tissue thickness, DBBM performed significantly better at 3 and 5 mm below the mucosal margin. From T1 to T2, no significant differences between groups were found at any level for soft tissue thickness and MBL. Conclusion At the aesthetic zone, advanced recession from tooth extraction to crown placement can be expected at sites treated with ARP regardless of biomaterial used. However, after crown insertion, tissue stability can be predicted.