Diagnosis of Mesiodistal Vertical Root Fractures in Teeth with Metal Posts: Influence of Applying Filters in Cone-beam Computed Tomography Images at Different Resolutions.

ABSTRACT

INTRODUCTION: The aim of this article was to evaluate the influence of applying filters in cone-beam computed tomography (CBCT) images at different resolutions. These CBCT images were obtained for diagnosing mesiodistal vertical root fractures (VRFs) in teeth with metal posts. METHODS: Forty teeth were treated endodontically, and 20 received metal posts. Ten teeth without posts and 10 teeth with posts were subjected to VRF in the mesiodistal direction. The sample was submitted to periapical radiographs and CBCT exams with a voxel of 0.25 and 0.30 mm. To reduce the influence of the metal artifact in the CT images, the teeth were evaluated with and without the application of filters ("Sharpen" and "Hard"). The images were evaluated by 2 radiologists who identified the presence of VRF. Accuracy values (receiver operating characteristic curves) for the different variables were compared by using analysis of variance and t test. RESULTS: No difference was observed between images with and without filter application (P > .05). Images obtained with a 0.25-mm voxel were more accurate (P < .05). The presence of the metal post reduced the accuracy of the diagnosis of VRF (P < .05), and the CBCT images showed superior results compared with periapical radiographs (P < .05). CONCLUSIONS: The presence of a metal post and the voxel size significantly interfere with the diagnosis of VRF. Despite the formation of metal artifacts associated with metallic cores, applying filters did not improve the diagnosis. For mesiodistal VRF, the CBCT images are superior to the periapical radiographs.