不同再治疗器械去除根充物效果的比较研究

The efficacy of different retreatment files on removing filling material from root canals

目的:评价H锉、Pro Taper Universal Retreatment和D-Ra Ce 3种根管再治疗器械去除根充物的效果。方法:将45颗因正畸拔除的单根管下颌前磨牙行根管充填后随机分为3组(n=15),分别用H锉(A组)、Pro Taper Universal Retreatment(B组)和D-Ra Ce(C组)再治疗锉配合氯仿溶剂去除根充物,记录到达工作长度的时间(T1)、预备完成所用总时间(T2),收集根尖外推出物并称重,从颊舌向和近远中向拍摄数码X线片,用Auto-CAD软件测量根管壁上残留充填物的覆盖面积,并评价其占整个根管壁面积的百分比。结果:所有样本根管内均有充填物残留,A组管壁充填物的残留量最少,明显低于B、C组(P<0.05),C组管壁充填物的残留量最多,高于B组(P<0.05)。与手用H锉相比,应用机用镍钛器械再治疗锉显著减少了再治疗所需的时间(P<0.05);B和C两组耗时无统计学差异(P>0.05)。B组根尖外推出物最多,高于C组和A组(P<0.05)。结论:使用机用镍钛再治疗器械,根管内残留物和根尖外推出物较多,但可缩短操作时间。

Objective：To evaluate the efficacy of hand instruments,Pro Taper Universal Retreatment nickel titanium（Ni Ti）file and D-Race on removing filling material from root canals. Method：Forty-five extracted single-rooted mandibular premolars were selected for this study. All samples were prepared to size 25 with the crown-down technique and obturated with laterally condensed gutta-percha and sealer. After radiographs were taken,the samples were randomly divided into3 groups（n=15）,respectively with H files（group A）,Pro Taper Universal Retreatment（group B） and D-Ra Ce（group C）nickel titanium file for removal of root canal filling materials. Chloroform was used as a solvent in the retreatment procedures. Following data were recorded：time to reach the working length（T1）and time required for the removal of gutta-percha（T2）;Eppendorf tubes were used to collect apical extrusion. The tubes were weighed before and after retreatment procedures. After completion of retreatment,bucco-lingual and mesio-distal radiographs were taken again,measurement of the percentage of remaining filling material was done in Auto-CAD software. Thereafter,data were analysed by means of one way ANOVA and Mann-Whitney U test at a 95% confidence level（P〈0.05）. Result：Residual filling material in group A was significantly less than those in group B and C（P〈0.05）,and Pro Taper Universal Retreatment performed better than DRa Ce（P〈0.05）. Compared with H file,D-Ra Ce and Pro Taper Universal Retreatment can reduce the time required for retreatment（P〈0.05）,but the difference between the latter two metheods was not statistically significant（P〈0.05）. The amount of apical extrusion generated by Pro Taper Universal Retreatment was the most（P〈0.05）. Conclusion：Under this experimental conditions,none of the retreatment files could completely remove the filling material from root canals.Pro Taper Universal retreatment and D-Ra Ce could significantly reduce the operating time,but resulted in more apical extrusion.