Cone beam CT technique has found wide application in dentistry. It is used in forensic dentistry, parodontology, the diagnosis of temporomandibular dysfunction, implantology and endodontics. This graduated thesis describes the working principle of cone beam CT unit and lists its advantages compared to conventional radiological examination. Through literature review describes the possible applications of CBCT in endodontics. In the field of endodontics CBCT is used for the following operations; Analysis of the morphology of the tooth root, the determination of their shape, number and localization of the channel, for the analysis of anatomical specificity, diagnostic errors occurring during endodontic therapy, diagnosis of root fracture, diagnosis of pulp-periodontal lesions and evaluate the success of treatment. Advantages of cone beam CT are multiple compared to conventional radiological examination. The accuracy and the ability to view images in all three dimensions are most important. For a good clinical outcome, good diagnostics are very important and cone beam CT device greatly contributes to this.