Buccal plate thickness as a predictor for endodontic microsurgery outcomes: A retrospective cohort study.

[OBJECTIVE] The aim of the study was to determine the relationship between preoperative buccal plate thickness (BPT) and radiographic healing at the osteotomy site after endodontic microsurgery (EMS) with and without guided tissue regeneration (GTR) using cone beam computed tomography (CBCT) imaging.

[STUDY DESIGN] The retrospective sample of 143 individuals who had EMS with pre- and postoperative CBCT scans available were divided into 2 groups: group 1 (GTR) and group 2 (no GTR), which were further divided into teeth where BPT was >1.0 mm or ≤1.0 mm. Bone healing was assessed by subjective evaluation of bone formation at the resected root surface (I), periapical bone formation (I), cortical plate formation (I), and a derived index (Author2-Author1 Indices) (I), calculated by a composite score of I and I.

[RESULTS] There was no significant impact on surgical healing with the use of GTR when BPT is >1.0 mm. The GTR had a significant impact on surgical healing when the BPT was ≤1.0 mm.

[CONCLUSIONS] This study supported the use of CBCT to evaluate three-dimensional healing after EMS. The Author2-Author1 index was found to be a clinically relevant method for assessing healing. To improve healing rate, the EMS cases with a preoperative BPT of ≤1.0 mm may benefit from GTR.