Clinical Diagnosis And Treatment Of C-shaped Root Canals In Mandibular Second Molars

Objective:This paper aims to study the diagnosis with X-ray films and microscopy and estimate the treatment of C-shaped root canals in mandibular second molars.Methods:The C-shaped root canals in 104 mandibular second molars were diagnosed by X-ray films and microscopy using Melton's method and AL-Fouzank's method, respectively. The preoperative radiographs, the initial apical file radiographs and obturation radiographs were examined by three experienced clinic dentists, who had enough knowledge about the c-shaped root canal system. The initial apical file radio-graph was classified and compared with Fan's small modification. The root canals were shaped by using Ni-Ti rotary instrument protaper and obturated with warm vertical compation technique. The type of C-shaped root canal, the success rate of diagosis and the in-operative complications were recorded. The efficiency of preparation and obturation was analyzed with radiographs before, during and after operation. The patient were reviewed after 3-6 months. The success rate of diagosis were analyzed using matched pair design, the level of significance was set to P<0.05.Result:1.The successful rate of the dignosis of the C-shaped root canal system with X-ray film and microscopy has been studied.The successful rates of diagnosis of X-ray film and microscopy were 67.4% and 90.7 %, separately. The frequency of C-shaped root canal in mandibular second molars was 41.3%. Moreover, there is obvious difference in them (P<0.05). The combination of X-ray films and microscopy could promote the successful rates of diagnosis. The initial apical file(IAF) and the obtruration radiograph could promote some clues about the morphology from middle to apical 1/3 part of the c-shaped root canal system.2.The effect of root canal preparation and obturation has been studied.There was no peforation, root canal offset, instrument fracture and other com-plication occur with Protaper Nickel-Titanium during root canal preparation in all cases. The taper and fluency have excellent treatment.The result showed that the short reexamination effect was steady after 3 or 6 months.Conclusion:Preoperative X-ray film and microscopy can improve the diagnosis of C-shaped root canal obviously. The C-shaped mandibular second molars can be treated very well with Ni-Ti rotary instrument and warm vertical compation technique.