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

objectives:The anatomic characteristics of C-shaped canal systems in mandibular second molars were observe and analyze. To diagnosis and treatment C-shaped canal systems in mandibular second molars, explore the clinical significance of cone-beam computed tomography(CBCT) and microscope and warm gutta—percha obturation.Methods:One hundred and seventeen of the mandibular second molars were extract which were treatment of acute pulpitis, chronic pulpitis,acute apical periodontitis and chronic apical periodontitis. After taking their preoperative radiographs,Observe and record the access cavity by dental operating microscope, we can diagnosis C-shaped canals in the mandibular second molars are fourty. According to the root canal orifice separate criteria which was proposed by Melton,C-shaped canal of those teeth had been diagnosed.Pro Taper file system to clean and shape all root canals,used ethylene diamine tetraacetic acid(EDTA)to clear the root canal and flushed the root canals with 3%Na OCLand saline alternately every time in root canal preparation.Used ultrasonic to clear C-shaped canal root. Twenty of C-shaped canals were filling with warm gutta—percha by vertical condensation technique. Twenty of C-shaped canals were filling with cold lateral condensation technique. Used CBCT in root canal therapy, when it is be needed. According X-ray and CBCT to evaluate effect of the root canal filling.Results:1.Microscopy: Forty of c-shaped can be diagnosis by X-ray and microscope. About 22 cases of X-ray showed a single root apical cone form or shape of the apical radius of convergence double root of the root of the C-shaped, 18 cases of patients teeth can not make judgments on the basis of newly diagnosed apical slice through a microscope confirmed.2. CBCT applications: One of C-shaped canal systems in mandibular second molars by microscope cannot diagnosed, but by CBCT diagnosed it is C-shaped root canal.3. By X-ray to evaluate C-shaped root canal filling effect: Twenty filled by warm gutta-percha obturation technique adequate filling frequency is 85%, Twenty filled by cold cold lateral condensation technique, adequate filling frequency is 75%, by applied χ2test analysis, P> 0.05, showing adequate filling frequency of warm gutta group slightly higher than the cold teether group, but no significant difference.4. By CBCT to evaluate C-shaped root canal filling effect: Twenty filled by warm gutta-percha obturation technique adequate filling frequency is 75%, Twenty filled by cold cold lateral condensation technique, adequate filling frequency is 25%, by applied χ2test analysis, P < 0.05, showing adequate filling frequency of warm gutta group have significant difference between the cold teether group.5. After C-shaped root canal therapy, compere X-ray and CBCT evaluate C-shaped root canal filling effect by applied χ2test analysis, P < 0.05, showing there was significantly difference between X-ray and CBCT, CBCT is one effective tool, CBCT can evaluate C-shaped root canal filling effect of three-dimensional.Conclusion:1.By X-ray cannot diagnosed it is C-shaped canal systems in mandibular second molars,microscopy improve its diagnosis and treatment effects.2. Using CBCT before root cannal therapy can confirm the diagnosis of C-shaped canal in mandibular second molars root canal: can guidance root canals prepare, effectively prevent the wall strip perforation, improve treatment success rate, Using CBCT to evaluation of root canal filling effect of three-dimensional are tight.3. C-shaped root canal were filling with warm gutta—percha by vertical condensation technique better than filling with cold lateral condensation technique. But not all the C-shaped root canal are suitable for warm gutta—percha. we should strictly control their indications. At the same time, not all C-shaped root canal were filling with warm gutta—percha are three-dimensional tight, which requires us to be rigorous work attitude,and constantly improve Clinical technology, enhancing the therapeutic effect of C-shaped root canal in mandibular second molar.