两种机用镍钛器械在模拟弯曲根管内的成形能力比较

Comparison of the formation ability of two types of machine-made nickel-titanium instruments in simulated curved root canals

目的比较机用镍钛器械Protaper Universal(PU)和M3?L在预备树脂模拟弯曲根管内的成形能力,为临床应用提供参考。方法选择20个树脂模拟弯曲单根管,随机分为2组,分别用PU镍钛锉和M3?L镍钛锉进行根管预备,记录根管预备时间、预备前后根管长度以及根管偏移量。结果 M3?L组在第4～7个测量位点测得的偏移量均小于PU组(P <0.05),在其余测量位点测得的两组偏移量之间差异无统计学意义(P>0.05);M3?L组预备根管前根管长度为(14.90±1.92)mm,预备根管后长度为(14.57±1.13)mm,两者间差异无统计学意义(t=3.18,P=0.058);PU组预备根管前根管长度为(14.53±1.53)mm,预备根管后长度为(14.28±1.39)mm,两者间差异无统计学意义(t=2.12,P=0.124);M3?L组[(110.15±10.43)s]平均预备时间少于PU组[(330.48±12.62)s](P <0.05)。结论 M3?L镍钛锉比PU镍钛锉在进行根管弯曲部位预备时具有较好的中心定位能力,且较省时。

Objective To compare ProTaper Universal(PU)and M3-L instruments in preparing curved root canals and to provide a reference for clinical applications.Methods Twenty resin-simulated curved single root canals were randomly divided into two groups.Root canal preparation was performed with a PU nickel-titanium file or an M3-L nick-el-titanium file.Root canal preparation time,root canal length before and after preparation and root canal deviation were recorded.Results In the M3-L group,the displacement measured at the 4th to 7th sites was less than that in the PU group(P<0.05),but there was no significant difference between the other two groups(P>0.05);The length of the root canal before and after root canal preparation in the M3-L group was(14.90±1.92)mm and(14.57±1.13)mm,respec-tively,and the difference between the two groups was not statistically significant(t=3.18,P=0.058).The root canal length before and after root canal preparation in the PU group was(14.53±1.53)mm and(14.28±1.39)mm,respec-tively.The difference between the two groups was not statistically significant(t=2.12,P=0.124);The average prepara-tion time of the M3-L group[(110.15±10.43)s]was less than that in the PU group[(330.48±12.62)s](P<0.05).Conclusion The M3-L nickel-titanium file has better central positioning ability and is less time-consuming than the PU nickel-titanium file in root canal bending preparation.