MTAN用于桩道清洁能力的实验研究

目的:研究MTAN在桩道制备后用于去除玷污层的能力。方法:经筛选得到符合要求的40颗单根管前磨牙,于釉牙骨质界冠方2mm处截去牙冠。根管预备、根管充填、桩道制备后随机均分为5组,分别用以下溶液进行桩道冲洗。A组:10mL0.9%盐水;B组:2.5mL3%NaOCl溶液+2.5mL18%EDTA溶液;C组:5mL3%NaOCl溶液+5mL18%EDTA溶液;D组:5mLMTAN溶液;E组10mLMTAN溶液。每组冲洗后,均用10mL0.9%盐水冲洗。在场发射扫描电镜下观察桩道内壁形态,用Peters’标准进行计分,记录数据并统计分析。结果:A组未能去除玷污层,牙本质小管口全部消失。B组残留大量厚的玷污层,较多的牙本质小管被堵塞;C组残存的玷污层覆盖面积达50%,牙本质小管部分开放。D组和E组玷污层大多数被去除,牙本质小管口多数开放。结论:MTAN可有效去除桩道预备后的玷污层。

Investigation on the Cleaning Capability of MTAN to Post Space Walls.

Objective: To investigate the cleaning capability of MTAN to the smear layer of post space walls after instrumentation. Methods: After screening, forty newly extracted premolars with single root canal were collected, and the crown parts of which were cut off above 2mm of enamelo-cemental junction. The root canals were shaped and obturated. Post space were prepared and divided randomly into 5 groups, and then irrigated by different solution: 10 ml of 0.9% saline (group A); 2.5 ml of 3% sodium hypochlorite followed by 2.5ml of 18% EDTA solution (group B); 5 ml of 3% sodium hypochlorite followed by 5ml of 18%EDTA solution (group C); 5ml of MTAN solution (group D); 10ml of MTAN solution (group E). All the samples were irrigated by 10 ml of saline ultimately. The morphology of post space was observed under field emission scanning electron microscope (FE-SEM), and scored by Peters’ criterion. Results: The smear layer existed in group A; a large amounts of thick smear layer were present and more dentin tubules were obturated in group B; the distribution of smear layer was up to 50% and the dentinal tubules were partly visible in group C; the smear layer was mostly removed in group D and E, and most of the dentinal tubules were open. Conclusion: MATN is effective to remove the smear layer after post space instrumentation.