两种镍钛机动器械根管预备的比较研究

目的:评价两种镍钛机动器械预备后牙弯曲根管的效果。方法:选择根管弯曲度10°~20°之间,及>25°的单根管前磨牙各24个,包埋于Branmante模型中。采用Hero642和Profile镍钛机动系统进行根管预备。测定根管预备前后根尖、根中、根冠段的牙本质切削面积、形态因子,并记录操作时间和器械折断情况。结果:Hero642对根尖段及重度弯曲根管根中段的牙本质切削大于Profile,在根管预备过程中体现出较短的操作时间和器械折断率;根管预备后的截面形态在两者间无显著差异。结论:Hero642和Profile镍钛机动系统具有良好的根管成形作用,较高的工作效率,可作为临床上弯曲根管的预备器械。

In vitro evaluation of root canal preparation using two rotary Ni- Ti instruments

AIM:To evaluate the root canal preparation of curved canals in posterior molars using two rotary Ni-Ti instruments.METHODS:Extracted human single-rooted premolars with root canal curvatures between 10 and 20 degrees and greater than 25 degrees(n=24canals in each case)were mounted in Branmante model.Root canals were prepared with two different Ni-Ti rotary instruments,Hero 642 and Profile.The dentin removal and shape factor in apical,middle and coronal third were measured pre-and post-instrumentation.In addition,preparation time and instrument fracture were recorded.RESULTS:Hero 642 removed more dentin at apical third and middle third of highly curved canals,took less preparation time and induced less instrument fracture in comparing to Profile.No statistical significant differences in shape factor were found between the two instruments at any level of the root.CONCLUSION:Hero 642 and Profile showed good shaping ability and high cutting efficiency,which is suitable for curved canal preparation in clinic.