In this quarter of a century, endodontic treatment has made great advances, where cone beam computed tomography （CBCT） has contributed greatly in regard to the improvement of diagnostic accuracy. This article aimed to summarize the application and effectiveness of CBCT in various aspects of endodontic treatment. Currently, international guidelines on the use of CBCT to endodontic diagnosis state that CBCT is recommended in complex, difficult-to-diagnose cases where conventional 2-dimensional radiography does not provide sufficient diagnostic yield. Our study on the diagnostic impact of CBCT imaging, involving 634 cases, revealed that CBCT was effective in the diagnosis and decision-making of complex endodontic cases. Our recent studies have also demonstrated that root fracture can be diagnosed accurately by means of analyzing the morphology of lesions 3-dimensionally reconstructed from CBCT images, and that CBCT imaging is effective at detecting periapical lesions that are undetectable on periapical radiography, particularly in the maxillary incisors and molars. Clinical cases in which CBCT imaging was useful in determining the number of canals, detecting root resorption, root perforation and root fracture and making presurgical planning are presented. It was concluded that CBCT is extremely effective for endodontic diagnosis.
