Analysis of the root canal configuration and C-shaped canal frequency of mandibular second molars: a cone beam computed tomography study

Background: Mandibular second molars frequently show variation in root canal configurations. The patients with C-shaped canals are quite challenging in dental practice. C-shaped canals have a poor prognosis in terms of debridement, obturation, and restoration. The aim of this study was to investigate the root canal configuration of mandibular second molar teeth and to determine the frequency of C-shaped canals in mandibular second molars. Materials and methods: We designed a retrospective study using cone beam computed tomography (CBCT) images and 256 CBCT images were retrieved from the archived records of Necmettin Erbakan University Faculty of Dentistry, Konya, Turkey. The root canal configurations were evaluated according to Vertucci's classification and C-shaped canal configurations were identified using the method of Fan et al. The frequency in percentages was calculated for C-shaped canals in CBCT scans. Results: Of the 444 mandibular second molars, the most frequent canal morphology in the mesial roots was Vertucci type IV (40.3%), followed by type II (27.5%). The distal roots were predominantly type I (92.9%), followed by types III (3.5%) and II (2.5%). Forty-seven (10.6%) teeth had C-shaped canals. Conclusions: Clinicians should be concerned about the different types of canal configurations. Knowledge of these anatomical variations will facilitate the endodontic practice.