Guided bone regeneration in peri-implant defects using a 1:1 mixture of cancellous and cortical freeze-dried bone allograft: A randomized controlled trial

Abstract

The results of guided bone regeneration (GBR) in peri-implant defects using anorganic bovine bone (ABB) were compared with those using a 1:1 mixture of cancellous and cortical freeze-dried bone allograft (FDBA). In total, 37 participants (10 males and 27 females) and 63 sites were evaluated. Full mucoperiosteal flap was reflected followed by implant insertion. The length and width of the defect were measured using a periodontal probe. Furthermore, the most buccal (Dis) and lingual (Dd) points of the exposed implant surface at the implant shoulder level were determined. The participants were randomly divided into two groups based on the graft material used: ABB only (control group) and 1:1 mixture of cancellous and cortical FDBA allograft (experimental group). Each transplanted site was covered by the collagen barrier membrane. After 5-6 months of surgery, re-entry was performed, and any residual defect length and width were measured. Moreover, the amount of regenerated bone was measured by calculating the distance from the Dis and Dd points to the regenerated bone in the buccolingual direction. Between-group comparisons were performed using the t-test. No differences in defect length, exposed implant surface, and horizontal bone gain were observed between ABB and allograft. Similarly, no significant differences in these measures and the defect width were observed between the two materials in both the maxilla and mandible. The 1:1 mixture of cancellous and cortical FDBA allograft combined with resorbable barrier membrane could be an effective alternative for ABB for the treatment of peri-implant defects when using GBR.