AIM: To compare ex vivo the diagnostic accuracy of cone beam computed tomography (CBCT) with periapical radiography in detecting artificially prepared incomplete and complete vertical root fractures (VRFs) in the presence of a gutta-percha root filling in human teeth. METHODOLOGY: The root canals of 20 extracted human premolar and molar teeth were radiographed and scanned with CBCT before a simulated VRF was induced (group 1). These teeth were radiographed and scanned with CBCT again after an incomplete (group 2) and complete (group 3) VRFs were induced. A suitably sized gutta-percha point was inserted into the prepared root canal prior to each series of radiographs and CBCT scans being taken. RESULTS: There was no improvement in the detection of artificially created vertical root fractures (VRF) in root filled teeth using CBCT compared with periapical radiographs. The overall area under the curve (AUC) value of incomplete and complete VRF was 0.53 for periapical radiography and 0.45 for CBCT (P = 0.034). The overall sensitivity of periapical radiography (0.05) was lower than CBCT (0.57) regardless of the extent of the VRF (P = 0.027). Periapical radiographs (0.98) had a higher overall specificity than CBCT (0.34) (P = 0.027). CONCLUSIONS: Under the conditions of this ex vivo study, periapical radiographs and CBCT were not accurate in detecting the presence and absence of simulated VRF. The imaging artefacts caused by the gutta-percha root filling within the root canal most probably resulted in the overestimation of VRF with CBCT and also the overall inaccuracy of this system.