Accuracy of Cone-Beam Computed tomography in diagnosis of root canal morphology of mandibular first molar

Abstract

Background and aims: A thorough knowledge about the morphology of root canals is an important prerequisite for root canal therapy. Dye penetration is the most common technique for the evaluation of root canal morphology and is used as a gold standard for determining the morphology of the root canal system. This technique cannot be used in vivo. Introduction of cone-beam CT revolutionized craniofacial complex imaging. Given the importance of knowledge about morphologic variations of the root canal system, a technique should be introduced with the highest accuracy and the least destructive potential and the capacity to be applied clinically. Therefore, the aim of the present study was to evaluate the accuracy of the results of cone-beam CT technique in determining the root canal morphology of mandibular first molars. Materials and methods: Ninety-six mandibular first molars extracted for periodontal reasons were collected. The teeth had mature apical foramina and had no canal calcification. Cone-beam CT images were prepared from the teeth and classified based on the system introduced by Vertucci and Gulabivala for root canal morphology. Subsequently, the same teeth underwent access cavity preparation and India ink was injected into the root canals using an insulin syringe. Then the teeth were demineralized with 5% nitric acid and the cleared teeth were finally evaluated under a magnifying glass at 5 to determine root canal system morphology. Data were compared between the two techniques. Kohens kappa test was used to evaluate agreement between the two techniques in relation to the type of the canals and ICC test was used to evaluate agreement between the two techniques in determining the number of the canals. Results: Agreement between the two techniques was observed in 52.6% of the cases (95% CI: 45.5459.66%), consisting of 28.1% in the mesial root canals (95% CI: 19.11%27.09%) and 77.1% (95% CI: 68.6985.51%) in the distal canals, with statistically significant differences (P<0.001). Conclusion: Under the limitations of the present study, it was concluded that tooth clearing technique for determining root canal system morphology of mandibular first molars is superior to CBCT technique.