摘要目的 比较两种单支锉技术预备离体磨牙弯曲根管的成形效果,为临床上寻求有效、安全、快捷的根管预备方法提供实验依据.方法 收集离体磨牙弯曲根管80个,编号后按随机数字表法分为4组,分别采用A(Reciproc)、B(OneShape)、C(Mtwo)和D(Revo S)4种镍钛器械行机动预备(分别为A、B、C、D组),记录单个根管预备的时间.各根管预备前后分别进行显微CT扫描,结合MeVisLab软件分析根管预备前后的牙本质去除量、未预备表面积百分比和根管偏移度.结果 在根管全长区域,各组间牙本质去除量、未预备表面积百分比和根管偏移度差异均无统计学意义(P＞0.05).在距根尖孔1 mm水平,A组的根管偏移度[中位数(四分位数间距)]为0.05(0.03)mm,显著小于B、C、D组[分别为0.05(0.04)、0.06(0.03)、0.06(0.04) mm](P＜0.05);A组根尖4mm区域根管表面积和体积增加量分别为(2.14±0.76) mm2、(0.38±0.15) mm3,均显著大于B组[分别为(1.61±0.71)mm2、(0.26±0.10) mm3]和C组[分别为(1.61±0.48) mm2、(0.25±0.11) mm3](P＜0.05),与D组[分别为(1.89±0.46) mm2和(0.30±0.16) mm3]相比差异无统计学意义(P＞0.05).A、B组的操作时间[分别为(86.3±24.6)和(85.9±21.3)s]均显著短于C、D组[分别为(147.4±28.3)和(126.3±27.7) s](P＜0.01).结论 与序列锉(C、D锉)技术相比,A、B两种单支锉技术在弯曲根管中均有良好的成形能力,且能提高根管预备效率.

abstractsObjective To compare the shaping quality in curved canals of two single-file technique systems with other two traditional full-sequential systems.Methods Eighty mature molar canals with the curvature between 20 and 45 degrees were randomly divided into four groups.Specimens in each group were prepared to size 25 at working length using A(Reciproc),B(OneShape),C(MTwo) and D(Revo S),respectively.Each canal was scanned by micro-computed tomography before and after preparation.Parameters including changes in dentine volume,percentage of uninstrumented area,degree and tendency of transportation were analyzed.The operating time was also recorded.Results In full canal length,there was no difference in canal dentine removal,instrumented percentage and transportation degree among four groups(P＞0.05).In the apical 4 mm region,group A removed more dentine[(2.14±0.76) mm2 of canal surface area and (0.38±0.15) mm3 of canal volume] than groups B and C(P＜0.05).At 1 mm level,median of transportation degree of group A was 0.05 (0.03) mm,which was smaller than other groups(P＜0.05).Groups A and B took (86.3±24.6) s and (85.9±21.3) s,while groups C and D took (147.4±28.3) s and (126.3±27.7) s srespectively to finish preparation.Single file techniques were significantly faster than the two fullsequential systems(P＜0.01).Conclusions Compared with the continuous rotary systems,the reciprocating single-file system A showed better apical shaping ability.Both single-file techniques were more efficient than full-sequential systems for curved canal preparation.Single-file techniques appear to be the effective and efficient method for curved canal preparation.