Divya K T, Satish G, Srinivasa T S, Reddy Veera, Umashankar K, Rao B Mohan
Lecturer, Department of Conservative Dentistry & Endodontics, Government Dental College & Research Institute, Vijayanagar Institute of Medical Science, Bellary, Karnataka, India.
Associate Professor, Department of Conservative Dentistry and Endodontics, Darshan Dental College & Hospital, Loyara, Udaipur, Rajasthan, India.
J Int Oral Health. 2014 Jul;6(4):12-7.
The purpose of the present study was to evaluate and compare the sealing ability of glass ionomer cement (GIC), composite resin, gray mineral trioxide aggregate (GMTA) and white mineral trioxide aggregate (WMTA) when placed coronally as double - sealing material over gutta-percha in root canal treated teeth.
A sample of 70 freshly extracted human single rooted teeth were cleaned, shaped and obturated with gutta-percha and AH Plus. The gutta-percha was reduced to a depth of 4 mm from the cemento enamel junction using hot plugger and standardized access cavities with 4 mm depth were prepared at the coronal ends of the roots. The specimens were randomly divided into four groups containing 15 teeth each depending on the restorations they received in the coronal cavity. A positive control group of five teeth received no restorative barrier over gutta-percha. All root surfaces were covered with two coats of nail varnish, leaving only the access openings uncovered except teeth in the negative control group, which were completely covered with nail varnish. All teeth were immersed in India ink, cleared and observed under stereomicroscope for the depth of dye penetration.
The results were tabulated and analyzed using Kruskal-Wallis test and multiple comparison between each group was carried out using Mann-Whitney test. The groups sealed with GMTA and WMTA showed least dye penetration than other groups and the difference was statistically significant. Highest dye penetration was seen with groups sealed with GIC and was statistically significant compared with other three groups.
The results showed that the GMTA and WMTA provided significantly better coronal seal when compared to other two restorations. The composite resin also showed significantly better seal than the unsealed group and the group sealed GIC, which showed highest leakage that was equivalent to that of unsealed group.
本研究的目的是评估和比较玻璃离子水门汀（GIC）、复合树脂、灰色三氧化矿物凝聚体（GMTA）和白色三氧化矿物凝聚体（WMTA）作为根管治疗牙齿中牙胶上方的双重封闭材料冠方放置时的封闭能力。
选取70颗新鲜拔除的人单根牙样本，进行清洁、预备根管形态并用牙胶和AH Plus进行充填。使用热充填器将牙胶从牙骨质牙釉质界处降低至4mm深度，并在牙根冠端制备深度为4mm的标准化入口洞型。根据冠部洞型所接受的修复材料，将标本随机分为四组，每组15颗牙。一个由5颗牙组成的阳性对照组在牙胶上方不设置修复屏障。所有牙根表面涂两层指甲油，仅保留入口开口处不涂，阴性对照组的牙齿则完全用指甲油覆盖。所有牙齿浸入印度墨水中，清理后在体视显微镜下观察染料渗透深度。
将结果列表并用Kruskal-Wallis检验进行分析，每组之间的多重比较采用Mann-Whitney检验。用GMTA和WMTA封闭的组显示出比其他组最少的染料渗透，差异具有统计学意义。用GIC封闭的组染料渗透最高，与其他三组相比具有统计学意义。
结果表明，与其他两种修复材料相比，GMTA和WMTA提供了显著更好的冠方封闭效果。复合树脂也显示出比未封闭组和用GIC封闭的组有显著更好的封闭效果，用GIC封闭的组显示出最高的微渗漏，与未封闭组相当。
