Impact of Root Canal Filling Quality on Periapical Status and Root Resorption in Orthodontically Treated Teeth: A...

The aims of the study were to assess the influence of root canal obturation quality on periapical status after orthodontic treatment and evaluate the association between gender and root resorption.

This retrospective radiographic study included 283 endodontically treated teeth from 199 patients (71 males, 128 females) treated with fixed appliances. Teeth were classified as adequate or inadequate based on the filling length, density/homogeneity, untreated canals, and coronal restoration integrity. Periapical status was assessed using the Periapical Index (PAI) on paired pre- and post-treatment panoramic radiographs. Chi-square, McNemar-Bowker, and Fisher's exact tests were used. Radiographically vital teeth from the same cohort were screened descriptively for incident periapical changes.

The PAI score distributions differed between the adequate and inadequate groups before (p = 0.001) and after treatment (p = 0.003). Temporal changes were not statistically significant within the groups (adequate, p = 0.236; inadequate, p = 0.148). After treatment, 26.99% of adequately filled and 60.83% of inadequately filled teeth remained or progressed to pathological PAI scores (3-5). Root resorption was more frequent in males (p < 0.05). In the vital-tooth screening, the baseline PAI was 1; three teeth developed radiolucency (PAI 4), and one developed a new radiopaque lesion.

Inadequate obturation was associated with a higher proportion of pathological periapical outcomes after orthodontic treatment, and male gender was associated with higher root resorption. These findings support the careful preorthodontic radiographic verification of endodontic quality.