Comparison of trabecular bone structure on periapical radiographs one year after apexification with MTA and regenerative endodontic treatment: a retrospective cohort study.

BACKGROUND: This study aimed to evaluate and compare periapical healing by analyzing the architecture of post-treatment trabecular bone using fractal analysis (FA) following mineral trioxide aggregate (MTA) apexification and regenerative endodontic treatment (RET), as well as to investigate the correlation between FA findings and Periapical Index (PAI). METHODS: A total of 37 patients (20 treated with apexification and 17 with RET) were included in the study. All selected teeth were single-rooted maxillary anterior incisors. Patients were divided into two groups based on the treatment received: either apexification or RET. At 12-month follow-up, periapical radiographs were obtained. From the designated regions of interest (ROI) on these radiographs, fractal dimension (FD) values were calculated, and PAI assessed by two observers were recorded. The Wilcoxon test was used to assess differences in time changes between measurements. Differences between groups were evaluated using the Mann-Whitney U test. Statistical significance was set at p < 0.05. RESULTS: There was a statistically significant difference between the FD of the ROI post-operatively and at follow-up in both, the apexification and the RET treatment groups (p < 0.001). No statistically significant difference was observed in the changes in FD at the 12-month follow-up between the apexification and the RET group (p > 0.05). In the apexification treatment group, a moderate negative correlation was observed between the changes in PAI and the changes in FD values (Spearman's rho = - 0.444, p = 0.049), indicating that increases in trabecular bone complexity (higher FD values) were associated with lower PAI. In contrast, in the RET group no statistically significant correlation was found between the changes in PAI and the changes in FD values (p > 0.05). CONCLUSION: Both MTA apexification and RET support structural bone healing in the periapical region. FA offers an objective approach for quantifying changes in trabecular bone architecture and may enhance the radiographic assessment of periapical healing when used alongside conventional methods. CLINICAL TRIAL NUMBER: Not applicable - retrospective analysis.