Biomaterials, Biomimetics and Biophotonics Research Group (B(3)), King's College London Dental Institute, Guy's Dental Hospital, London, UK.
Dent Mater. 2012 Jun;28(6):622-31. doi: 10.1016/j.dental.2012.02.005. Epub 2012 Mar 17.
The aim of this study was to assess by using confocal microscopy (CLSM), AFM nano-indentation and microtensile bond strength test (μTBS) the quality of the resin-dentin interfaces created with selected bonding parameters.
Dentin conditioned with H(3)PO(4) or EDTA was bonded in ethanol- or water-wet condition using a HEMA-free or HEMA-containing adhesive. The resin-bonded teeth were stored in distilled water (24h) and sectioned as match-sticks (0.9 mm(2)) for μTBS. Further resin-bonded teeth were sectioned and analyzed using CLSM, and AFM nano-indentation. The AFM imaging and nano-indentation processes were undertaken using a Berkovich diamond indenter. The modulus of elasticity (Ei) and hardness (Hi) across the interface were evaluated with the specimens in a fully hydrated status. The AFM imaging was performed both in dry and wet conditions for evaluating the shrinkage of the hybrid layer on dehydration.
The HEMA-containing adhesive applied onto H(3)PO(4)-etched ethanol or water-wet dentin created hybrid layers with the lowest biomechanical nano-properties (p<0.05); no significant differences in μTBS were found between the two wet-bonding techniques (p>0.05). However, the ethanol-wet bonding reduced the dye penetration into the adhesive layer created with the HEMA-containing adhesive. Hybrid layers with high biomechanical properties, low micropermeability and no shrinkage were only possible when using HEMA-free adhesive applied in ethanol wet-dentin. In particular, a significant increase in Ei and Hi was achieved at the hybrid layer and underneath the resin-dentin interface of ethanol-wet EDTA-treated dentin.
The use of HEMA-free adhesives applied onto ethanol-wet dentin may be considered as an alternative and suitable bonding strategy to achieve high quality resin-dentin interfaces.
本研究旨在通过共聚焦显微镜（CLSM）、原子力显微镜纳米压痕和微拉伸结合强度测试（μTBS）评估使用选定的粘结参数制备的树脂-牙本质界面的质量。
使用 HEMA 自由或包含 HEMA 的黏合剂，在 H3PO4或 EDTA 处理的牙本质上，在乙醇或水湿条件下进行粘结。将粘结后的牙齿在去离子水中储存 24 小时（24h），并切成火柴棒（0.9mm2）用于 μTBS。进一步将粘结后的牙齿切割并使用 CLSM 和原子力显微镜纳米压痕进行分析。使用 Berkovich 金刚石压头进行 AFM 成像和纳米压痕过程。评估在完全水合状态下界面的弹性模量（Ei）和硬度（Hi）。在干燥和湿条件下进行 AFM 成像，以评估在脱水时混合层的收缩。
应用于 H3PO4蚀刻的乙醇或水湿牙本质的 HEMA 含黏合剂会形成具有最低生物力学纳米特性的混合层（p<0.05）；两种湿粘结技术之间的 μTBS 无显著差异（p>0.05）。然而，乙醇湿粘结减少了 HEMA 含黏合剂形成的黏合剂层中的染料渗透。只有当使用 HEMA 自由黏合剂在乙醇湿牙本质上应用时，才能形成具有高生物力学性能、低微渗透性和无收缩的混合层。特别是，在乙醇湿 EDTA 处理的牙本质的混合层和树脂-牙本质界面下，Ei 和 Hi 显著增加。
在乙醇湿牙本质上应用 HEMA 自由黏合剂可能被视为一种替代且合适的粘结策略，以实现高质量的树脂-牙本质界面。
