Evaluating the effectiveness of cone-beam computed tomography reverse contrast images in the diagnosis of vertical root fractures: An in vitro pilot study

Abstract Introduction: The aim of this study is to investigate the effectiveness of cone-beam computed tomography (CBCT) reverse contrast images in the diagnosis of vertical root fractures (VRFs). Materials and Methods: In this study, 20 single-canal premolar teeth without cracks and internal resorption were selected and after root canal treatment, divided into two: experimental and control groups. In each of the teeth in the experimental group, an artificial fracture was created with the SANTAM device, then the teeth of both groups were randomly placed in the dental sockets of a dry mandible, and after preparing CBCT images of the teeth, the images were processed by reverse contrast software. Initial and reverse contrast images were examined by two radiologists and two endodontists. The data were analyzed by SPSS software version 22. Results: Observers reported higher sensitivity and positive and negative predictive value in normal contrast images than in reverse contrast images, but the specificity reported by endodontists in reverse contrast images was slightly higher than in normal contrast images. In comparing the results of radiologists and endodontists, there was a significant agreement in the review of the initial images (κ =0/59), but there was no significant agreement in the images with reverse contrast (κ = −0/1). There was not any notable distinction observed in the assessment of normal and reverse contrast images among the observers, nor in the comparison between radiologists and endodontists, except for the examination of normal contrast images by the two groups of radiologists and endodontists ( P = 0.00). From this, it can be inferred that the diagnostic power of reverse contrast images in identifying VRFs is inferior to that of normal contrast images ( P > 0.05). Conclusion: According to the obtained results, it was concluded that reverse contrast CBCT images are not effective in diagnosing VRFs and cause error in diagnosis.