FlexMaster镍钛机用器械根管再治疗清理效果的体外研究

目的研究FlexMaster镍钛机用器械根管再治疗清理的效果。方法选取临床拔除的40颗单根管前牙,用改良式逐步后退法进行根管预备,牙胶尖与碧兰糊剂侧方加压充填根管。放置30d后随机分为两组,A组用H型锉去除根管内旧充填物,B组用FlexMaster镍钛机用器械去除充填物。分别记录操作时间。然后,将牙根纵劈,立体显微镜下观察根管冠1/3、根中1/3和根尖1/3段的残留物情况。结果在根管冠1/3处两种方法的根管清理效果无统计学差异（P〉0.05）。在根管的中段和根尖段,B组的残留物量较A组少,两组间存在显著性差异（P〈0.05）。B组操作时间明显少于A组,两组间也有显著性差异（P〈0.01）。结论与手用H型锉相比,FlexMaster镍钛机用根管预备器械去除根管旧充填物效果更好,且操作时间显著减少。

In vitro study of the efficacy of FlexMaster NiTi rotary instruments in root canal retreatment

Objective To study the retreatment effectiveness of FlexMaster NiTi rotary instruments.Methods 40 extracted single-rooted anterior teeth were divided into two groups,20 in each.They were instrumented by modified step-back flare technique and obdurated with gutta-percha and cortisomol sealer using lateral condensation.Retreatment of group A was performed by H files,group B by using FlexMaster NiTi rotary instruments.The time of retreatment was recorded.The teeth were then split longitudinally into halves.The remaining gutta-percha/sealer on the apical,middle,coronal parts of the root canal walls were visually scored with a stereomicroscope.Results In the apical and middle sections,less residual filling material was observed in group B than in group A(P<0.05).The mean operating time of group B was significantly less than that of group A.Conclusions The retreatment effectiveness of FlexMaster is better than that of H files.