Yavari Hamidreza, Samiei Mohammad, Eskandarinezhad Mahsa, Shahi Shahriar, Aghazadeh Marzieh, Pasvey Yones
Department of Endodontics, Dental School, Tabriz University of Medical Sciences, Tabriz, Iran ; Dental and Periodontal Research Center, Dental School, Tabriz University of Medical Sciences, Tabriz, Iran.
Iran Endod J. 2012 Summer;7(3):156-60. Epub 2012 Aug 1.
A coronal barrier in root-filled teeth is one of the most effective methods for prevention of coronal microleakage. The aim of this study was to compare coronal microleakage of three materials [light-cured glass-ionomer (GI), mineral trioxide aggregate (MTA), and composite resin] as coronal barriers.
A total of 188 intact maxillary incisors were used. After instrumentation, all the canals were obturated with gutta-percha and lateral condensation technique using AH26 sealer. Then, the teeth were sectioned just apical to the cemento-enamel junction. The roots were randomly assigned to three experimental groups (n=56) and two negative and positive control groups (n=20). After placing the orifice barrier, the samples were immersed in 2% methylene blue solution for 2 weeks at 37°C. Then the teeth were longitudinally sectioned mesiodistally and dye penetration was measured under a stereomicroscope at ×10 magnification. Data were analyzed with one-way ANOVA and a post-hoc Tukey test.
The positive control group leaked significantly more than all the experimental groups (P=0.001). MTA exhibited less leakage than composite and GI (P=0.002) but no significant differences were found between GI and composite groups.
Immediate placement of a suitable intra-orifice barrier like MTA, before final restoration, may help minimize recontamination of the remaining apical gutta-percha.
在根管充填的牙齿中设置冠部屏障是预防冠部微渗漏最有效的方法之一。本研究的目的是比较三种材料[光固化玻璃离子水门汀（GI）、三氧化矿物凝聚体（MTA）和复合树脂]作为冠部屏障时的冠部微渗漏情况。
共使用188颗完整的上颌切牙。根管预备后，所有根管均采用AH26封闭剂，通过牙胶尖侧向加压充填技术进行充填。然后，在牙骨质-釉质界根尖方将牙齿截断。将牙根随机分为三个试验组（n = 56）以及两个阴性和阳性对照组（n = 20）。放置根管口屏障后，将样本置于37°C的2%亚甲蓝溶液中浸泡2周。然后将牙齿沿近远中方向纵切，在体视显微镜下以×10放大倍数测量染料渗透情况。数据采用单因素方差分析和事后Tukey检验进行分析。
阳性对照组的渗漏明显多于所有试验组（P = 0.001）。MTA的渗漏比复合树脂和GI少（P = 0.002），但GI组和复合树脂组之间未发现显著差异。
在最终修复前立即放置合适的根管口屏障，如MTA，可能有助于减少剩余根尖牙胶尖的再污染。
