The Study Of Diagnosis And Obturation About The C-Shaped Canal System In Mandibular Second Molars

Objectives: The purpose of this study was to evaluate the efficacy ofpreoperative and the operating microscope to recognize C-shaped canal system in mandibular second molars and to find out the best methods of the root canal obturation.Methods: Collect 90 the second mandibular molars extracted for variousreasons. After taking their preoperative radiographs, we grand and cleaned the pulp cavities. Observe and record the form of root canal orifice by the operating microscope and then take the initial apical file radiographs. Analyze the success rate of diagnosing C-shaped root canal system through preoperative radiographs and operating microscope and evaluate the importance of the initial apical file radiographs to judge the anatomical form of them. After that, classify those teeth which had been diagnosed into three groups and obturated them with three different materials. Examine and record the different effects.Results: Among those C-shaped mandibular molars, we could diagnose 20out through the preoperative radiographs and 28 through the operating microscope. Combine these two methods, we could diagnose 31 out .According to the initial apical file films,we could diagnose that 13 belong to the typeâ… , 8typeâ…¡, 10 typeâ…¢. Dyeing lines of warm gutta-percha obturation was shortest ,which was significantly shorter than other two groups(P <0.01).Conclusions: We should combine the preoperative radiographs and the operating microscope to promote the diagnosis of the C-shaped canal system .The initial apical file films had great meanings in the classification of C-shaped canal system. The microleakage of warm gutta-percha obturation was the least and which was the best method.