Ballal Suma, Venkateshbabu Nagendrababu, Nandini Suresh, Kandaswamy Deivanayagam
Department of Conservative Dentistry and Endodontics, Meenakshi Ammal Dental College, Maduravoyal, Chennai, India.
J Endod. 2008 Apr;34(4):478-80. doi: 10.1016/j.joen.2008.01.020.
The aim of our study was to assess the setting time and surface crazing of glass ionomer cement when layered over partially set mineral trioxide aggregate (MTA). To assess setting time, 40 hollow, cylindrical stainless steel molds were taken and equally divided into 4 groups. In groups I, II, and III glass ionomer cement was layered over partially setting MTA at 45 minutes, 4 hours, and 3 days, respectively. Group IV was used as a control. An additional 50 specimens were prepared for assessment of surface crazing. Twenty specimens (groups I and II) were prepared to study normal and desiccated patterns of conventional glass ionomer cement, respectively. Thirty specimens (groups III, IV, and V) were prepared by layering glass ionomer cement over partially set MTA at various time intervals. All the specimens were stained with red ink and analyzed for craze lines by light microscopy. From our study, it was observed that there was no statistical difference in setting time of glass ionomer cement when layered over partially set MTA in comparison to that of the control group. No craze lines were observed in those specimens (groups III, IV, and V) when viewed under staining and light microscopy. It could be concluded that conventional glass ionomer cement might be layered over partially set MTA after 45 minutes and could be used for single visit procedures.
我们研究的目的是评估玻璃离子水门汀覆盖在部分凝固的三氧化矿物凝聚体（MTA）上时的凝固时间和表面裂纹情况。为了评估凝固时间，取40个中空圆柱形不锈钢模具并平均分为4组。在第I组、第II组和第III组中，分别在45分钟、4小时和3天时将玻璃离子水门汀覆盖在部分凝固的MTA上。第IV组用作对照。另外制备50个样本用于评估表面裂纹情况。制备20个样本（第I组和第II组）分别研究传统玻璃离子水门汀的正常和干燥模式情况。通过在不同时间间隔将玻璃离子水门汀覆盖在部分凝固的MTA上制备30个样本（第III组、第IV组和第V组）。所有样本均用红墨水染色，并通过光学显微镜分析裂纹线。从我们的研究中观察到，与对照组相比，当玻璃离子水门汀覆盖在部分凝固的MTA上时，其凝固时间没有统计学差异。在染色和光学显微镜观察下，在那些样本（第III组、第IV组和第V组）中未观察到裂纹线。可以得出结论，传统玻璃离子水门汀在45分钟后可覆盖在部分凝固的MTA上，并可用于一次性治疗程序。
