Comparison of orthodontic root resorption of root-filled and vital teeth using micro-computed tomography

Objective: To evaluate the difference in orthodontic root resorption between root-filled and vital teeth. Material and Methods: Sixteen individuals who required bilateral premolar tooth extraction due to orthodontic treatment and had a previously root-filled premolar tooth on one side were included in the study. The experimental group consisted of root-filled premolar teeth, and the control group consisted of contralateral vital premolar teeth. A 150-g buccally directed force was applied to these teeth using 0.017x0.025-inch TMA cantilever springs. The premolars were extracted 8 weeks after the application of force. Images were obtained using micro-computed tomography. Resorption measurements were obtained using the Image J program. Results: The mean values for resorption were 0.08869 mm(3) for the root-filled teeth and 0.14077 mm(3) for the contralateral teeth, indicating significantly less resorption for the root-filled teeth compared with the contralateral teeth after the application of orthodontic force (P = .003). In both groups, the most resorption was seen on the cervical-buccal and apical-lingual surfaces. The mean resorption value of the cervical region was 0.06305 mm(3) in the control group and 0.0291 mm(3) in the experimental group, and the difference was statistically significant (P = .002). Conclusions: Root-filled teeth showed significantly less orthodontic root resorption than vital teeth.