Diagnosis Of C-Shaped Canal System In Mandibular Second Molars

Objective: The purpose of this study was to evaluate the efficacy of preoperative and the operating microscope to recognize C-shaped mandibular second molars and to investigate the anatomical features of C-shaped canal system through the initial apical file(IAF) radiographs.Materials and methods: A total of 86 madibular second molars being considered as needing root canal therapy were included in this study. Diagnosis of C-shaped canal system was based on the configuration of canal orifice observed under the operating microscope in conjunction with the radiographic canal morphology of the preoperative radiographs. The preoperative radiographs and the orifices shape under the operating microscope were analyzed to recognize the C-shaped canal system respectively and the initial radiographs of the verified C-shaped canal systems were classified according to the radiographic features of C-shaped canal system.Results: Of the 86 mandibular second molars, 52 were diagnosed as having C-shaped canal system through the preoperative radiographs in conjunction with the operating microscope, 38 and 46 of which can be recognized from the preoperative radiographs and the operating microscope respectively. According to the IAF films, 20, 14 and 18 were classified as radiographic type I, n and â…¢ respectively.Conclusions: The number of recognized C-shaped canal system can be promoted according to the preoperative radiographs in conjunction with the orifices shape under the operating microscope. The anatomical structure of apical third can be revealed by IAFradiograph especially in type I C-shaped canal system.