Abstract: Objective: To explore volume rendering technique of root canal morphology based on CBCT images. Methods: 32 mandibular incisors with complete root and apex and without endodontic treatment were collected and 8 patients with 32 mandibular incisors all the CBCT images were scanned at HZ mode for volume rendering. Before reconstruction, the root canal morphology was evaluated using the axial images and images using multiple planar reconstruction(MPR) technique. Simplant was used for indirect volume rendering. The number of root canal was evaluated based on the reconstructed images. Results: The accuracy of evaluation of root number for mandibular incisors was 96.9% in vitro and 93.4% in vivo with VR technique. There were no significant differences between MPR and VR for evaluation the number of root canal using fisher's exact test. Conclusion: VR technique is a visual and accurate method to show a second canal for mandibular incisors.

Key words: Cone beam, CT , Root canal morphology , Volume rendering