Khalilak Zohreh, Vali Tabasom, Danesh Farzad, Vatanpour Mehdi
Department of Endodontics, Dental Branch, Islamic Azad University, Tehran, Iran.
Iran Endod J. 2012 Winter;7(1):10-4. Epub 2012 Mar 1.
Mineral trioxide aggregate (MTA) has been suggested as an effective material for apical barrier, forming an effective seal against bacterial leakage in teeth with open apices. MTA needs moisture for setting; which can come from the apical region or a moist cotton pellet. This study was intended to compare bacterial leakage in one- and two-step MTA apical barrier technique in open apices with different diameters.
The root canals of 52 extracted human maxillary incisors were prepared and open apices in two different diameters of 1 and 1.4 mm were created. The samples put in experimental groups randomly. A 4-mm thickness of MTA was placed as apical barrier for both one- and two-step methods. In one-step groups (1.4 mm diameter; n=12 and 1 mm diameter; n=12), the samples were obturated immediately after placing MTA plug. For two-step groups (1.4 mm diameter; n=12 and 1 mm diameter; n=12), a moist cotton pellet was placed over the MTA plug for 3 days before root canal obturation. Four samples served as positive/negative control groups. After one week, microleakage was evaluated using bacterial penetration technique and results were statistically analyzed utilizing SPSS software and Chi-square test.
In one-step technique 13 and in two-step technique 12 samples showed bacterial leakage. There was no statistically significant differences between two techniques (Chi square, P=1). The difference between the results related to 1 and 1.4 mm apical foramens was also not significant (P=1). Also 12 and 13 samples showed bacterial contamination in teeth with 1 mm and 1.4 mm apical foramens, respectively (P=1).
It seems that leakage of MTA apical plug using one- and two-step technique is comparable; however, in vivo investigations are highly recommended for more accurate results.
矿物三氧化物凝聚体（MTA）已被认为是一种用于根尖屏障的有效材料，可在根尖开放的牙齿中形成有效的密封以防止细菌渗漏。MTA凝固需要水分，水分可来自根尖区域或湿润的棉球。本研究旨在比较不同直径根尖开放的牙齿采用一步法和两步法MTA根尖屏障技术时的细菌渗漏情况。
制备52颗拔除的人上颌切牙的根管，并创建两种不同直径（1毫米和1.4毫米）的根尖开放。将样本随机放入实验组。对于一步法和两步法，均放置4毫米厚的MTA作为根尖屏障。在一步法组（直径1.4毫米；n = 12和直径1毫米；n = 12）中，放置MTA栓后立即进行根管充填。对于两步法组（直径1.4毫米；n = 12和直径1毫米；n = 12），在根管充填前，在MTA栓上放置湿润的棉球3天。四个样本作为阳性/阴性对照组。一周后，采用细菌渗透技术评估微渗漏情况，并使用SPSS软件和卡方检验对结果进行统计学分析。
一步法中有13个样本，两步法中有12个样本显示细菌渗漏。两种技术之间无统计学显著差异（卡方检验，P = 1）。与1毫米和1.4毫米根尖孔相关的结果差异也不显著（P = 1）。此外，分别有12个和13个样本显示根尖孔为1毫米和1.4毫米的牙齿存在细菌污染（P = 1）。
似乎一步法和两步法使用MTA根尖栓的渗漏情况相当；然而，为获得更准确的结果，强烈建议进行体内研究。
