3种机用镍钛根管锉中心定位能力的比较

Centering Ability of Three Rotary Nickel-titanium Instruments in Simulated Canals:A Comparative Study

目的比较3种机用镍钛根管锉预备树脂模拟弯曲根管的中心定位能力差异,为临床应用提供实验室依据。方法把30个树脂模拟弯曲根管(弯曲度30°)按照随机数字表分为3组,分别用Reciproc(R组)、Protaper(P组)和WaveOne(W组)机用镍钛根管锉进行根管预备,定位拍摄预备前后模拟弯曲根管的数码照片。应用Photoshop软件进行预备前后图像的提取和重叠。应用Digimizer软件在11标尺条件下测量距离根尖孔每1mm根管中心点在预备前后的偏移量,每根管测量10个位点。用单因素方差分析和Student-Newman-Kuels检验进行统计学检验(α=0.05)。结果在距离根尖1、2和3mm水平上,3组根管中心点向弯曲外侧偏移;在6、7和8mm水平上,3组根管中心点向弯曲内侧偏移,且R组和W组的中心定位能力优于P组,差异有统计学意义(均P<0.05),R组和W组的中心定位能力差异无统计学意义(均P>0.05)。在距离根尖4、5、9和10mm水平上,各组之间的根管中心定位能力差异无统计学意义(均P>0.05)。结论 Reciproc和WaveOne的中心定位能力相近,且比Protaper在根尖区和根管弯曲最大部位具有更好的中心定位能力。

Objective To compare the centering ability of three rotary nickel-titanium instruments Reciproc,Protaper and WaveOne in resin-simulated curved root canals.Methods A total of 30 resin-simulated curved canals（curvature=30°）were divided into 3 groups（n=10 each）using the random number table.They were prepared with Reciproc（group R）,Protaper（group P）and WaveOne（group W）respectively.Pre-and post-operative images were obtained by a digital camera at the fixed position,and superimposed through Photoshop.The center displacement between pre-and post-operative images were measured at 10 points beginning at 1mm from the end point of the canal with the software Digimizer at a ratio of 1 to 1.The data were analyzed through one-way ANOVA and Student-Newman-Kuels at a significance level ofα=0.05.Results The central point was shifted laterally to the curve at 1,2,and 3 mm from the end point of the canal,while it shifted medially to the curve at 6,7,and 8mm.The centering ability was better in groups R and W than in group P with significant differences noted（P0.05）.No significant difference was found in the centering ability between group R and group W.Also there were no significant differences in the centering ability at 4,5,9and 10 mm among the three groups（P0.05）.Conclusion Reciproc and WaveOne have similar centering ability.They preform better in terms of centering location than Protaper,especially at the apex and the most curved part of the canal.