Application of sonic instrumentation in C-shaped root canals of mandibular molars

AIM:To compare the treatment effects of two root canal preparation methods-sonic instruments cooperated with stainless steel hand instruments and stainless steel hand instruments only to prepare C-shaped root canal of mandibular molars. METHODS:Two hundred and thirty-eight cases of C-shaped root canals of mandibular molar were randomly divided into two groups. Root canals in the experimental group ( 119 teeth and 232 root canals) were prepared with MM1500 sonic instrument and mobile phones Rispisonic filed needle,while root canals in the control group ( 119 teeth and 224 root canals) were prepared with stainless steel hand instruments. Both groups were sealed with glycerine-calcium hydroxide paste for a week,and then were filled with AH-plus and cold lateral conden-sation technique. Complications and filling quality of two techniques were compared and evaluated. RESULTS:There was less pain and emergency after filling in the experimental group than in the control group ( P 0. 05) ,but there was no significant difference in terrace formation between the two groups ( P 0. 05). The filling quality in the experimental groups was significantly better than that in the control group ( P 0. 05). After one-year follow-up,the success rate in the experimental group was significantly higher than that of the control group ( P 0. 05). CONCLUSION:Using sonic instruments cooperated with stainless steel hand instruments to prepare C-shaped root canals of mandibular molars can reduce postoperative pain and acute disease,and improve the quality of root canal filling and the curative effect.