Abstract: Objective: To evaluate the quality of hot gutta-percha root canal filling in the mandibular molar in the elderly by cone-beam CT. Methods: Eighty molars with 253 root canals in 51 geriatric patients from June 2015 to August 2016 in the Stomatology Hospital of Dalian were selected. Before the operation, the molars were scanned with cone-beam CT. The root canals were filled with hot gutta-percha and vertical pressurized. The quality of root canal filling were evaluated by cone-beam CT and digital images. Results: The error rate of root canal length observed by digital images was 9.1%. The difference of evaluation result of digital images in mouth and cone-beam CT was statistical significance (P＜0.05). The error rate of the root canal adaptation of digital images at 2.0% was evaluated. The differences of digital images and cone-beam CT results were no statistical significance. Conclusion: Cone-beam CT has a higher accuracy in evaluating the hot gutta-percha root-filling quality of mandibular molar of the geriatric patients than digital images.

Key words: Cone-beam computed tomography, Mandibular molar , Hot gutta-percha, Root-filling quality , Geriatric patients