不同冲洗剂对桩道玷污层清除能力的体外研究

Investigation on the efficacy of different irrigation to remove the smear layer on post space in vitro

目的评价不同冲洗剂对桩道壁玷污层的清除能力。方法经筛选,选择符合条件的单根管前磨牙20颗,于釉牙骨质界上方2 mm水平去除冠方牙体组织。根管预备,根管充填。3M钻逐级进行桩道预备3号。随机均分为4组,即生理盐水组、双氧水组、次氯酸钠组+MTAN组、MTAN组,分别用以下溶液冲洗:5 ml生理盐水、5 ml 3%H_2O2、2.5 ml3%次氯酸钠+2.5 ml MTAN、5 ml MTAN。每样本冲洗结束后,均用5 ml生理盐水溶液终末冲洗。于颊舌侧沿牙体长轴纵向劈开。每试样展示较好的一半在场发射扫描电镜下观察。根据Peters'标准计分,对数据行统计学处理。结果生理盐水冲洗桩道后,玷污层覆盖整个牙本质壁。双氧水冲洗桩道后,大量的玷污层残留,绝大多数牙本质小管被阻塞。次氯酸钠+MTAN和MTAN均可以去除大部分的玷污层,大量的牙本质小管口开放。4组样本的统计结果差异有统计学意义(P<0.05)。结论 MTAN及次氯酸钠+MTAN均可有效去除桩道预备后产生的玷污层。

Objective To evaluate the efficacy of different irrigation to remove the smear layer on post space.Methods After screening following experimental requirements,twenty single-canal premolars were selected. The crowns were cut above 2 mm of the cemento-enamel junction. The root canals were shaped and obturated. After post space preparations,the teeth were randomly assigned to 4 groups of 5 specimens each such as normal saline group,hydrogen peoxide（ H_2O2） group,sodium hypochlorite（ Na OCl） ＋ MTAN group,MTAN group. The specimens of four groups were flushed by 5 ml of normal saline,5 ml of 3% H_2O2,2. 5 ml of 3% Na OCl ＋ 2. 5 ml MTAN,5 ml MTAN separately. All the specimens were irrigated with 5 ml of normal saline finally,then were longitudinally split into halves. The better half of every specimen was observed under Field Emission Scanning Electron Microscope（ FESEM） and scored according to Peters＇ criterion. The data were statistically analyzed using software SPSS 19. 0.Results The smear layer existed throughout the entire post space in normal saline group. Large amouts of smear layer were present and more dentin tubules were obturated in H_2O2 group. The smear layer was removed almost in Na OCl ＋ MTAN group. Comparision of the four groups showed significant difference（ P〈0. 05）. Conclusion MTAN and Na OCl ＋ MTAN could remove the smear layer effectively.