Clinical diagnosis and treatment of C-shaped root canals in mandibular second molars

Objective To discuss the incidence, diagnosis, and treatment of C-shaped root canals in mandibular second molars.Methods The C-shaped root canals in 152 mandibular second molars were diagnosed by X-ray films and canal exploration using Melton's method. The root canals were shaped by using Ni-Ti rotary instruments Hero 642,cleaned by using ultrasonic irrigation with sodium hypochlorite, and obturated with vertical condensation technique for C-shaped root canals. The efficiency of preparation and obturation was analyzed with radiographs before, during and after operation. The prognosis was evaluated by patients' signs, clinical examination, and recall radiographs.Results The frequency of C-shaped canals in mandibular second molars was 32.2%. According to the X-ray films, 79.6% of teeth with C-shaped canals had fused roots, and 20.4% of C-shaped canals teeth revealed the distinct mesial and distal roots. There was no any complication in all cases. The result of treatment was good.Conclusion The C-shaped canal system in mandibular second molars has the radiograph image showing a fused root or distinct mesial and distal roots, which could be diagnosed by X-ray films and canals exploration. The C-shaped mandibular second molars can be treated very well with rotary instrumentation, ultrasonic irrigation with sodium hypochlorite, and vertical condensation technique.