Aim: The purpose of this study was to determine the incidence of clinically and radiographically recognized C-shaped canal systems in mandibular second molars treated in the Department of Conservative Dentistry and Endodontics at the Government Dental College and Research Institute, Bangalore during 2008-2009 in a sample representing a Bangalore population., Methods: 100 patients were selected randomly requiring root canal treatment of mandibular second molar over a 1-year period. The incidence of C-shaped canals was revealed following radiographic and clinical examination. Two pre-operative radiographs were taken using the shift cone technique and clinical investigation was conducted by scrutinizing the pulp chamber and canal entrance following access., Results: C-shaped canalsoccurred more frequently below 40 years; females had a greater (5.7%) predilection than males 1.9%); single rooted teeth (4%) more than two rooted teeth (1%). A total of 5 Cshaped canals were recognized clinically and 12 by radiographic method. Out of the 12, only 3 canals were confirmed clinically. The proportion of C-shaped teeth detected by radiographic method was significantly lower than the proportion of clinically diagnosed cases., Conclusion: 5% exhibited a C-shaped canal configuration and clinical method was more efficient in diagnosis of this canal variation than the radiographic method.

Key Words: mandibular second molar, canal configuration, C-shaped canal.