Vertical root fracture (VRF) is one of the most severe root complications which can be found among root canal treated teeth with a rate of 3.7% to 30.8%.Fracture line is visible radiographically provided that the difference between central beam and fracture line is only 4 degrees. Superimposition of other structures, low sensitivity, and lack of three-dimensional view makes the radiographic diagnosis difficult. Cone beam computed tomography (CBCT) imaging technique provides faster and more accurate diagnosis of vertical fractures by creating three-dimensional images.Metal artifact is one of the CBCT imaging artifacts that is generated as a result of beam hardening which can make diagnosis difficult and time-consuming by decreasing contrast and concealing structures. Various methods for artifact reduction (AR) on CBCT have been proposed.This study aimed to assess the diagnostic accuracy of CBCT using different voxel sizes with and without metal artifact reduction algorithm compared to digital intraoral periapical radiography.120 Single rooted extracted human teeth were selected and endodonticaly treated. Each Eight teeth were embedded in each acrylic block. After post insertion, the teeth were divided equally and randomly into 2 groups, one with induced root fracture and the other group with intact teeth. Every tooth in the two groups was imaged by standardized digital paralleling periapical radiography and CBCT (CBCT without metal artifact reduction algorithm), (CBCT without metal artifact reduction with high resolution) and (CBCT with metal artifact reduction and high resolution).The results showed that the highest diagnostic accuracy was found with CBCT with metal artifact reduction and high resolution followed by CBCT without metal artifact reduction algorithm and then CBCT without metal artifact reduction with high resolution. The lowest diagnostic accuracy was found with digital periapical radiography.Changing the voxel size from 133µm to 85 µm did not improve the diagnostic accuracy. Using the metal artifact reduction algorithm improved the diagnostic accuracy but with no statistically significant difference.From the present work, the following conclusions could be reached:1.In case of clinical suspicious of vertical root fracture with negative findings on two dimensional radiographic examination, CBCT is the imaging modality of choice to confirm presence or absence of fractures.2.Using voxel size of 133µm is sufficient to accurately detect vertical root fracture.3.In case of presence of metallic posts, CBCT with metal artifact reduction algorithm can be used to detect vertical root fractures.