Department of Dental Surgery, Faculty of Dental Surgery, Medical School, Mater Dei Hospital, University of Malta, Msida MSD 2080, Malta.
Dent Mater. 2011 Sep;27(9):870-8. doi: 10.1016/j.dental.2011.04.013. Epub 2011 May 11.
Many dental materials are used in contact with each other in sandwich techniques. Liners, bases and permanent restorative materials are placed adjacent to each other and allowed to set under the same conditions. The same applies for endodontic materials where irrigating solutions and root canal dressings come in contact with root canal obturating materials and root-end fillers. The aim of this research was to investigate the material interface of mineral trioxide aggregate (MTA) in contact with non-setting calcium hydroxide paste (CH), glass ionomer cement (GIC) and intermediate restorative material (IRM).
All materials were mixed according to manufacturer's instructions. Freshly mixed MTA (Dentsply) was placed in a plastic container and another dental material was compacted on it while still unset. These materials included GIC (Fuji IX), non-setting calcium hydroxide (Calasept) and IRM (Dentsply). The materials were allowed to set for 28 days at 37°C and 100% humidity. The layered materials were sectioned longitudinally embedded in resin and polished to expose the interface between the two materials. Scanning electron microscopy (SEM) was performed of the interface and X-ray energy dispersive analysis (EDX) was conducted at 50 μm intervals to establish elements present at specific distances from the material interface.
The calcium hydroxide paste did not affect the hydration of MTA. Migration of silicon, aluminum and bismuth from the MTA to the CH occurred. The GIC exhibited a high degree of micro-cracking and some porosity in the interfacial region. Strontium from the GIC was detected at 200 μm within the MTA. The zinc from the IRM cement was detected at 100 μm within the MTA. The zinc affected the hydration of the MTA leading to retardation of setting and increased porosity.
MTA interacts with other dental materials with resultant elemental migration in adjacent materials. Zinc oxide eugenol based cements should be avoided in the presence of MTA as zinc causes retardation of cement hydration with increased porosity. Glass ionomer cements absorb the water of hydration from the MTA also resulting in increased porosity and incomplete hydration of MTA.
许多牙科材料在三明治技术中相互接触。衬垫、基底和永久性修复材料彼此相邻放置，并在相同条件下凝固。根管冲洗液和根管封闭剂与根管填充材料和根尖封闭剂接触的情况也是如此。本研究的目的是研究接触未凝固氢氧化钙糊剂（CH）、玻璃离子水门汀（GIC）和中间修复材料（IRM）的矿物三氧化物聚合体（MTA）的材料界面。
根据制造商的说明混合所有材料。将新鲜混合的 MTA（登士柏）放入塑料容器中，并在其仍未凝固的情况下在其上压实另一种牙科材料。这些材料包括 GIC（富士 IX）、未凝固的氢氧化钙（Calasept）和 IRM（登士柏）。将分层材料在 37°C 和 100%湿度下放置 28 天凝固。对界面进行扫描电子显微镜（SEM）检查，并在 50μm 的间隔进行 X 射线能量色散分析（EDX），以确定在距材料界面特定距离处存在的元素。
氢氧化钙糊剂不会影响 MTA 的水合作用。硅、铝和铋从 MTA 迁移到 CH 中。GIC 在界面区域表现出高度的微裂纹和一些孔隙率。在 MTA 内 200μm 处检测到 GIC 中的锶。在 MTA 内 100μm 处检测到 IRM 水泥中的锌。锌会影响 MTA 的水合作用，导致凝固延迟和孔隙率增加。
MTA 与其他牙科材料相互作用，导致相邻材料中的元素迁移。在存在 MTA 的情况下，应避免使用氧化锌丁香酚基水泥，因为锌会导致水泥水合作用延迟，增加孔隙率。玻璃离子水门汀也会从 MTA 中吸收水合水，导致孔隙率增加和 MTA 不完全水合。
