Biopure MTAD去除根管壁玷污层效能的体外实验研究

目的采用离体牙评价Biopure MTAD作为根管冲洗液去除根管壁玷污层的能力。方法将40颗人单根牙随机分为5组进行根管预备。各组根管预备过程中和预备完成时的冲洗液分别为：A组蒸馏水，B组5.25% NaClO和17% EDTA，C组1.3% NaClO，D组1.3% NaClO和Biopure MTAD，E组1.3% NaClO和3% EDTA。预备完后将样本纵向剖开，在扫描电镜下观察，评价根管壁玷污层和腐蚀情况。结果A组和C组实验样本整个根管壁都有玷污层覆盖。B、D、E组牙根冠和中1/3区根管壁玷污层均被有效去除，3组间无统计学差异（P＞0.05）；D组根尖1/3区根管壁基本无玷污层，与B、E组相比有统计学差异（P＜0.05）。B组根冠和根中1/3的根管壁的腐蚀度较大，与D、E组相比有统计学差异（P＜0.05）；根尖1/3区各组根管壁的腐蚀度无统计学差异（P＞0.05）。结论Biopure MTAD与1.3%的NaClO联合使用能更有效去除根管壁玷污层且对根管壁表面的结构无明显破坏。

Effect of Biopure MTAD on removing smear layer in vitro

Objective To evaluate the ability of Biopure MTAD in removing smear layer in vitro. Methods Forty extracted single-rooted human teeth were randomly divided into five groups：Distilled water in group A, 5.25% NaClO and 17% EDTA in group B, 1.3% NaClO in group C, 1.3% NaClO and Biopure MTAD in group D, 1.3% NaClO and 3% EDTA in group E. The canals were prepared and irrigated with one of the five different irrigating agent respectively. The amount of smear layer and erosion on the surface of the root canal walls were examined with scanning electron microscope. Results The whole surfaces of root canals in group A and C were covered by smear layer. The surfaces of root canals in the coronal and middle thirds of samples in group B, D, E were free of smear layer（P＞0.05） and the apical third of canals in the group D were significantly cleaner（P＜0.05） than that in group B and E. The coronal and middle sections were significantly eroded in group B compared with group D and E（P＜0.05）. The degree of erosion in the apical section was not statistically different among group B, D and E （P＞0.05）. Conclusion Biopure MTAD and 1.3% NaClO are effective irrigating agents for removal of the smear layer on the surface of root canal. There is no significant change in the structure of the surface of root canal.