Effect of allograft and collagen membrane application on periapical and labial bone regeneration in apicomarginal defects treated with endodontic microsurgery: a randomized controlled trial.

[OBJECTIVE] To evaluate effectiveness of guided tissue regeneration (GTR) using an allograft and collagen membrane versus non-GTR for apicomarginal defects using endodontic microsurgery at 1-year follow-up.

[STUDY DESIGN] Thirty healthy adult patients with apicomarginal defects requiring periradicular surgery were randomly assigned to either study group (n = 15) or control group (n = 15). Study group received allograft and bioresorbable collagen membrane, while control group underwent surgery without GTR. Both groups were treated using endodontic microsurgery by same operator, following standardized protocol. Clinical and radiographic evaluations were conducted at baseline and after 12 months. Periapical healing was assessed using Rud and Molven's criteria on periapical radiographs and modified PENN 3D criteria for cone-beam computed tomography (CBCT) scans. Labial bone height was also measured with CBCT. Statistical analyses included descriptive statistics, Mann-Whitney, Wilcoxon rank-sum tests, and Fisher's exact test, with significance set at P < .05.

[RESULTS] Clinical outcomes were favorable in both groups. 2D periapical healing assessment showed 100% success in study group versus 86.6% in control group (P = .143). 3D periapical healing success rate was 80% in both groups. Labial alveolar bone regeneration was significantly higher in study group (17.64 ± 19.76%) compared to control group (4.74 ± 13.14%) (P = .023).

[CONCLUSION] At 1-year follow-up, study findings indicated that use of allograft and collagen membrane in GTR significantly improves labial alveolar bone regeneration in apicomarginal defects treated with endodontic microsurgery.