Prevalence of C-shaped canal morphology of first and second mandibular molars using Cone-Beam Computed Tomography

Introduction: Due to the importance of familiarity with root canal morphology in order to completely clear the canal and achieve treatment success, the aim of this study was to use Cone-Beam Computed Tomography (CBCT) images to evaluate the frequency and anatomy of C-shaped canals in the first and second mandibular molars. Materials and Methods: In this cross-sectional study, CBCT images of 209 patients (435 teeth) were evaluated to determine the presence of C-shaped canals and their anatomical morphologies along the root, based on Fan classification. Bilateral or unilateral occurrence of C-shaped canals and their relationship with gender, age and tooth location were examined and statistically analyzed using the chi-square test and SPSS 17 software. The significance level was P < 0.05. Results: CBCT images from 209 patients, 103 patients (49.3%) were female and 106 (50.7%) were male. Out of 435 teeth (157 mandibular first molars and 278 mandibular second molars) evaluated, 33 specimens (7.5%) including the 2 first molars (1.27%) and 31 second molars (11.15%) had a C-shaped canal system which were from 25 patients (2 first molars in 2 patients and 31 second molars in 23 patients). The prevalence of bilateral C-shaped canals was among the 97 patients with bilateral second molars (6.18%). There was also no significant relationship between teeth position, gender and the prevalence of C-shaped canals. Conclusion: The configuration of C-shaped canals extensively changes along the length of the root and should be considered during preparation and obturation of root canal system.