应用锥形束 CT 评价两种机用镍钛根管锉的根管成形能力

摘要

目的：应用锥形束 CT 评价 Twisted File（TF）和 ProTaper 两种机用镍钛锉的根管成形效果。方法：选择符合标准的离体牙41个（共60个单根管牙根），按弯曲度分为轻度弯曲（0°～15°）组和重度弯曲（16°～35°）组（n ＝30）：每个大组再随机分为两个亚组（TF 组和 ProTaper 组，n ＝15）。机用 TF 锉和 ProTaper锉分别预备根管，预备前后进行 CBCT 扫描，测量距根尖2、4、6 mm 处根管近、远中侧的根管壁厚度，计算各处的轴中心率，比较其差异。结果：TF 和 ProTaper 机用镍钛根管锉中心定位能力间差异均无统计学意义（P ＞0．05），TF 预备轻度弯曲根管时的中心定位能力优于重度弯曲根管（P ＜0．05）；ProTaper 预备轻度弯曲根管在距根尖2、4 mm 处的中心定位能力优于重度弯曲根管（P ＜0．05），而6 mm 处差异无统计学意义（P ＞0．05）。结论：两种机用镍钛根管锉均有较好的中心定位能力，牙根弯曲度＜15°时的中心定位能力优于＞15°者。%AIM:To evaluate the shaping ability of Twisted File(TF)rotary system and ProTaper by CBCT. METHODS:60 single root canals in 41 extracted teeth were divided into 2 groups according to the canal curvature:0°~15°group and 16°~35°group.Then,each group was divided into two subsets and prepared by TF and ProTaper respectively.Canals were scanned by CBCT scanner before and after instrumentation.The width of dentine removed was measured at three points (2 mm,4 mm and 6 mm to root tip).Incidence of canal aberrations was recorded and an-alyzed statistically using T-test.RESULTS:No significant difference was found between TF and ProTaper instruments (P >0.05).Centralizing ability of the 2 systems was better when canal curvature was between 0°and 15°than that between 16°and 35°(P <0.05).CONCLUSION:Under the conditions of this study,both TF and ProTaper NiTi rotary systems can keep satisfactory preservation of the original canal shape.