Torabinejad M, Smith P W, Kettering J D, Pitt Ford T R
Department of Endodontics, School of Dentistry, Loma Linda University, California, USA.
J Endod. 1995 Jun;21(6):295-9. doi: 10.1016/S0099-2399(06)81004-6.
This study investigated the marginal adaptation of mineral trioxide aggregate (MTA) as a root-end filling material, compared with commonly used root-end filling materials by scanning electron microscopy (SEM). Eighty-eight single-rooted freshly extracted human teeth were cleaned, shaped, and obturated with gutta-percha and root canal sealer. Following root-end resection and cavity preparation, the root-end cavities were filled with amalgam, Super-EBA, Intermediate Restorative Material (IRM), or MTA. Using a slow-speed diamond saw, 40 roots were longitudinally sectioned into two halves. Resin replicas of resected root ends of the remaining nonsectioned roots were also prepared. After mounting longitudinal sections of roots and resin replicas of resected roots on aluminum stubs, the distance between the test root-end filling materials and surrounding dentin was measured at four points under SEM. Examination of the original samples showed numerous artifacts in the longitudinal sections of the specimens. In contrast, the resin replicas of resected and filled root ends had no artifacts. Statistical analysis of data comparing gap sizes between the root-end filling materials and their surrounding dentin shows that MTA had better adaptation compared with amalgam, Super-EBA, and IRM.
本研究通过扫描电子显微镜（SEM），调查了三氧化矿物凝聚体（MTA）作为根尖充填材料的边缘适应性，并与常用的根尖充填材料进行了比较。八十八颗新鲜拔除的单根人牙经过清洁、预备根管形态，并用牙胶尖和根管封闭剂进行充填。在进行根尖切除和窝洞预备后，根尖窝洞分别用银汞合金、Super-EBA、中间修复材料（IRM）或MTA进行充填。使用低速金刚石锯将40颗牙根纵向切成两半。还制备了其余未切片牙根根尖切除部分的树脂复制品。将牙根的纵切片和根尖切除部分的树脂复制品安装在铝制短柱上后，在扫描电子显微镜下于四个点测量受试根尖充填材料与周围牙本质之间的距离。对原始样本的检查显示，标本的纵切片中有大量伪像。相比之下，根尖切除并充填后的牙根树脂复制品没有伪像。对根尖充填材料与其周围牙本质之间间隙大小数据的统计分析表明，与银汞合金、Super-EBA和IRM相比，MTA具有更好的适应性。
