Structural Analysis of Interface between Dentin and Adhesive Restorative Materials

采用扫描电子显微镜（SEM）、透射电子显微镜（TEM）和共聚焦光学显微镜对粘接界面进行了形态分析，其中扫描电子显微镜是最简单的方法。然而，扫描电镜有一个固有的缺点，即样品必须气相包覆金，并在高真空条件下观察。由于脱水导致样品损坏，使得观察含有粘合剂材料的水变得困难。最近开发的环境扫描电镜可以在无金涂层和极低真空条件下使用。本研究采用光镜、冷冻扫描电镜和环境扫描电镜观察光固化恢复性聚烯酸玻璃胶合剂（Fuji II LC CAPUSULE和vitremer）表面处理（牙本质调理剂和CA-Agent）和未处理的粘附界面的超微结构。此外，在冷冻扫描电镜下，采用硝酸银染色技术研究了牙本质-水泥界面的特征。切片标本的显微观察发现，几乎所有标本的光固化玻璃聚烯酸盐胶粘剂片段都保留在制备的牙本质空洞底部，在界面处没有形成任何间隙，并且在脱钙牙本质的表层上存在透明的薄层。在水泥-牙本质界面处观察到一层没有未反应核的薄水泥基质层。结果表明，骨水泥基质可以浸渍脱钙牙本质的表层，但对脱钙牙本质的深层渗透不足。在骨水泥-牙本质界面未观察到粘接树脂修复体的混杂区等层。

Morphological analysis of the adhesive interface has been performed using the scanning electron microscope (SEM), transmission electron microscope (TEM) and confocal optical microscope, with the SEM being the simplest method among them. However, SEM has an inherent drawback that samples must be vapor coated with gold and observed under high vacuum condition. Sample damage due to dehydration makes observation difficult for water containing adhesive materials. Recently developed Environmental-SEM can be used without gold coating and extremely low vacuums condition. The purpose of this study was to observe ultrastructure of adhesive interfaces of light-cured restorative glass polyalkenoate cements (Fuji II LC CAPUSULE and vitremer) with or without surface treatment (Dentin Conditioner and CA-Agent) by using light microscopy, Cryo-SEM,and Environmental-SEM.Furthermore, the characteristics of the dentin-cement interface were examined by using a silver nitrate staining technique under the Cryo-SEM.Microscopic observation of sectioned specimens revealed that some segments of light-cured glass polyalkenoate cement were retained on the prepared dentin cavity floor without any gap formation at the interface in almost all specimens and a transparent thin layr was present on the superficial layr of the decalcified dentin. A thin cement matrix layr without unreacted core was observed at the cement-dentin interface. It was suggested that the cement matrix might impregnate the superficial layr of decalcified dentin, however, insufficient penetration into the deep layr was observed. A layr such as the hybrid zone for adhesive resin restorations was not observed at the cement-dentin interface.