上颌第一前磨牙根管及根管峡区再治疗的实验研究

目的：评估不同再治疗技术清理根管及峡区内根充物的效果。方法：30颗单牙根双根管的上颌第一前磨牙采用热牙胶连续波充填技术充填后分为3组去除根充物：A组，不锈钢器械（K锉和H锉）；B组，不锈钢器械（K锉和H锉）＋除丁克溶剂；C组，ProTaper再治疗器械＋除丁克溶剂。记录操作时间。各组用除丁克暂封5min，再使用Endo Activator冲洗，拍摄X线片，评价根管内根充物残留量。结果：A组操作时间显著高于B组和C组（P〈0．05）。B组和C组清洁效果优于A组。根管内暂封除丁克及使用Endo Activator冲洗后残留物显著少于器械操作即刻结束的残留物（P〈0．05）。结论：各种再治疗方法均不能彻底清除根管及峡区内的根充物，除丁克和Endo Activator有助于减少根充物残留。

Retreatment Efficiency of Isthmus in Maxillary First Premolars

Objective.. To evaluate the efficacy of three retreatment methods for gutta--percha and sealer removal from root canals with isthmus. Methods： Thirty extracted maxillary first premolar with single root and two canals were selected and prepared using rotary ProTaper instruments and filled with gutta-percha and AH Plus using continuous wave of condensation technique. These teeth were divided into three groups randomly （n= 10） ： Group A, stainless steel hand files （K--files and Hedstr6m files ） ; Group B, stainless steel hand files （K--files and Hedstr6m files ）＋Desocclusol; Group C, ProTaper Universal retreatment instruments＋ Desocclusol. Retreatment was con sidered complete for all groups when no filling material was observed on the instruments. The operating time and the filling material remnants were recorded. Then the three groups were filled with Desocclusol for 5 minutes and irrigated by EndoActivator system. The residual filling materials were recorded. Results： The operating time in Group A was statistically higher than Group B and Group C（P〈0.05）. Group B and Group C left cleaner root canal walls than Group A. There were statistically significant cleaner in the root canals in teeth by filled with Desocclusol and irrigated by EndoActivator（P〈0.05）. Conclusion： Irrespective of different techniques used, all the specimens had some remnants on the root canal. Desocclusol and EndoActivator proved to be useful for removing residual ob turation materials.