The Efficacy of Metal Artifact Reduction Mode in Cone-Beam Computed Tomography Images on Diagnostic Accuracy of Root Fractures in Teeth with Intracanal Posts

Introduction: The purpose of this study was to evaluate the efficacy of cone-beam computed tomography CBCT in the diagnosis of RF in the presence of an intracanal posts with and without applying “metal artifact reduction” (MAR) mode. Methods and Materials: This in vitro study included 60 single-canal endodontically treated premolars. Post spaces were created in all roots. RFs were simulated in 30 of the 60 teeth. Dentatus posts were cemented in 15 of 30 roots with and without RFs. Teeth were arranged randomly in 6 artificial dental arches. Images were taken using a Vatech CBCT machine with and without MAR (MAR and WMAR, respectively). A radiologist and an endodontist evaluated the CBCT images for the presence of RFs. Sensitivity, Specificity, positive and negative predictive values were determined for each mode. MC Nemar’s and Kappa tests were used for data analysis. Results: The percentage of correct diagnosis using the WMAR mode in both the post space and pin groups in the presence of root fracture was 46.6%; with MAR, it increased to 86.6% and 66.6%, respectively. There was no significant difference between two modes in post space (P=0.503) and metal pin groups (0.549). The overall sensitivity of VRF diagnosis in WMAR mode was 46.67%; in MAR mode, sensitivity was 76.67%. The specificity of WMAR and MAR modes were 60% and 53.33%. The levels of agreement between two modes and real findings were less than 0.45. Conclusions: There were no significant differences between the efficacies of imaging modes. The sensitivity of the MAR mode for diagnosis of VRF in both the pin and post space groups was higher than the WMAR mode. The specificity of MAR in comparison with WMAR was less or equal in dental groups. The agreement between CBCT and real findings was poor.Keywords: Artifact; Cone-Beam Computed Tomography; Diagnosis; Tooth Fracture; Vertical Root Fractur

Accuracy of Cone-beam Computed Tomography in Comparing with Clearing and Staining Method in Evaluating the Root Canal Morphology: An In Vitro Study

Introduction: In order to successfully perform root canal treatment, thorough knowledge of the root canal anatomy is essential. Cone-beam computed tomography (CBCT) has the ability to improve our understanding of the root canal system. The goal of the present study was to compare the accuracy of CBCT in revealing the number and form of the root canals of different maxillary and mandibular teeth with clearing and staining method. Methods and Materials: CBCT images were taken from 80 extracted human teeth fixed in agar arch models. The number and configuration of the root canals of each tooth were determined by the two observers. Then the teeth were cleared and stained. Two endodontists evaluated the number and forms of the root canals. The accuracy of CBCT was determined and compared with clearing and staining by Fisher’s exact test. The agreement of two methods in detection of the number and form of the root canals were evaluated by Kappa test, P≤0.05. Results: CBCT accurately detected the number of root canals in 129 (92.1%) of 140 roots and the form of the canals in 119 (85%) of the roots. There was no significant difference between the accuracy of CBCT in the detection of the number (P=0.13) and forms (P=0.4) of root canals of maxillary and mandibular teeth. The agreement between CBCT, and tooth clearing and staining in detection of the number of root canals was excellent in the maxilla (kappa=0.88±0.05) and good in the mandible (kappa=0.720±0.097). The agreement between the two methods in demonstration of the form of root canals was good in both maxillary (kappa=0.73±0.07) and mandibular (kappa=0.67±0.09) teeth. Conclusion: CBCT provides accurate information about root canal morphology. Application of this technique could result in more successful endodontic treatments.Keywords: Anatomy; Cone-beam Computed Tomography; Root Canal