Mtwo镍钛系统在根管再治疗中的性能评价

Evaluation of the quality of Mtwo NiTi instruments system in root canal retreatment

目的评价机用Mtwo镍钛系统在根管再治疗中的性能。方法选取30颗正畸拔除双根管前磨牙,随机分为3组:塑化治疗组,根充再治疗组(行冷牙胶侧方加压根管充填),首次根管治疗组,每组10颗牙,20个根管。30 d后将这3组中的每一个组均随机分为2组,分别用手用不锈钢器械及Mtwo镍钛系统清理预备根管。记录和比较各组的操作时间、器械折损及根管再通情况。结果①三组组内比较发现,使用Mtwo镍钛系统的平均操作时间均较使用手用不锈钢器械少(P<0.05)。②在使用Mtwo镍钛系统时,首次根管治疗组需要的时间最少,塑化治疗组需要的时间最多,根充再治疗组使用的时间居中(P<0.05);使用手用不锈钢器械时,结果相同。③在实验初期有1例器械折损。④在塑化治疗组中有3个使用手用不锈钢器械疏通的根管未完全再通,其余根管均再通成功。结论 Mtwo镍钛系统去除根管内充填物及预备根管的操作时间较手用不锈钢器械少。

Objective To evaluate the property of Mtwo NiTi instruments system in root canal retreatment. Methods Thirty extracted premolars teeth （60 root canals） were collected, and randomly divided into three experimental groups. The teeth were obtura- ted with FR phenolaldehy deagent in group A, filled with gutta-percha cone and sealer in group B, and firstly treated in group C. After 30 d, the three groups were grouped randomly：stainless steel hand files group and Mtwo NiTi instruments group. The operation time, broken files and negotiated canals were recorded. Results （1）The mean operation time in Mtwo NiTi instruments subgroup was signif- icantly shorter than that in stainless steel hand files subgroup in three groups （ P 〈 0.05 ）. （2）The mean operation time was gradually de- creased from group C, group B to group A （ P 〈 0.05 ）. （3）At the beginning of the experiment, one file was broken. （4）In group A, three root canals treated with stainless steel hand files failed, and the other root canals succeeded. Conclusion The operation time of Mtwo NiTi instruments is shorter than that of stainless steel hand files.