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 0.017 × 0.025-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.