3种器械去除根管内牙胶充填物的效果评价

目的：比较H型锉和两种再治疗镍钛旋转器械去除根充物的效果。方法：45颗离体单根管下颌前磨牙,使用ProTaper镍钛器械根管预备,热牙胶垂直加压根管充填。标本随机分为3组（n=15）用不同方法去除根充物。A组H型锉、B组ProTaper Universal和C组Hero Shaper,分别记录再治疗所用时间。将标本沿牙体长轴纵劈,用立体显微镜观察根管壁残留的牙胶,t检验和单因素的方差分析one way ANOVA进行统计学分析。结果：B组根管内残留充填物的量较其他两组更少（P〈0.05）;B、C两组操作时间明显短于A组（P〈0.05）,而B、C两组间,C组用时较少,但没有显著性差异。结论：根管再治疗中,所有器械均会残留根充物,ProTaper Universal镍钛再治疗器械可以有效去除单根管下颌前磨牙根管内充填物。

Efficacy of Three Instruments in Removing Gutta-Percha and Sealer from the Root Canal Walls

Objective：To evaluate the efficacy of two NiTi rotary instruments and H file for gutta-percha（GP）removal from root canals in vitro.Methods：Forty-five mandibular premolars with one canal were used in this experimental study.They were instrumented with ProTaper NiTi rotary instruments and hot vertical condensation technique obturated.The teeth were randomly divided into three groups of 15teeth each.Removal of gutta-percha was performed with H-File,ProTaper Universal and Hero Shaper.The teeth were split longitudinally and the area of remaining gutta-percha/sealer on the root canal wall was explored under stereomicroscope.Retreatment time duration was also recorded for each sample.Data were analyzed statistically by One-way ANOVA and t-test.Results：Group B left significantly less remaining filling materials than group A and C（P〈0.05）.The mean time of retreatment in group B and C were significantly shorter than group A（P〈0.05）.Group C were more rapid than Group B but no significant differences were observed.Conclusion：No system removed the root filling materials entirely.The ProTaper Universal rotary retreatment system proved to be an efficient method of removing GP and sealer from mandibular premolars.