Hashimoto Masanori, de Gee Anton J, Feilzer Albert J
Division of Biomaterials and Bioengineering, School of Dentistry, Health Sciences University of Hokkaido, 1757 Kanazawa, Ishikari-Tobetsu, Hokkaido 061-0293, Japan.
Dent Mater. 2008 Oct;24(10):1304-10. doi: 10.1016/j.dental.2008.02.008. Epub 2008 Apr 18.
In a previous study on of polymerization contraction stress determinations of adhesives bonded to dentin a continuous decline of stress was observed after the adhesives had been light-cured. The decline was ascribed to stress relief caused by diffusion into the adhesive layer of water and/or solvents, left in the impregnated dentin surface after drying and/or evaporation in the application procedure. The purpose of the present study was to test the hypothesis that the contraction stress of adhesives bonded to enamel will not decline after light-curing, based on the assumption that water and/or solvents are more efficiently removed from impregnated enamel surfaces in the drying and/or evaporation step.
Contraction stress was determined in a tensilometer for three total-etching adhesives Scotchbond multi-purpose, Single bond and One-step plus and four self-etching adhesives Clearfil SE Bond, Clearfil Protect Bond, AdheSE, and Xeno III. The adhesives were placed in a thin layer between a glass plate and a flat dentin or enamel surface pre-treated with phosphoric acid or self-etching primer and light-cured under constrained conditions.
All adhesives bonded to enamel showed a stress decline, but significantly less than for dentin with the exception of two self-etching adhesives. The greatest decline was found for the total-etching adhesive systems bonded to dentin. The presence of hydrophobic monomers in the adhesives had a significant influence on the decline.
The experiments indicate that fluids are withdrawn from the resin impregnated tooth structures, which may result in small defects in the tooth-resin interfaces.
在先前一项关于测定粘结于牙本质的粘合剂聚合收缩应力的研究中，观察到粘合剂光固化后应力持续下降。这种下降归因于在应用过程中干燥和/或蒸发后残留在浸渍牙本质表面的水和/或溶剂扩散到粘合剂层中所导致的应力释放。本研究的目的是基于这样一种假设来检验该假说，即粘结于牙釉质的粘合剂在光固化后收缩应力不会下降，该假设认为在干燥和/或蒸发步骤中，水和/或溶剂能更有效地从浸渍的牙釉质表面去除。
在拉力试验机中测定三种全酸蚀粘合剂（Scotchbond多用途粘合剂、单组分粘合剂和一步加粘合剂）以及四种自酸蚀粘合剂（Clearfil SE Bond、Clearfil Protect Bond、AdheSE和Xeno III）的收缩应力。将粘合剂置于玻璃板和平板牙本质或经磷酸或自酸蚀底漆预处理的牙釉质表面之间的薄层中，并在受限条件下进行光固化。
所有粘结于牙釉质的粘合剂均显示应力下降，但除两种自酸蚀粘合剂外，其下降幅度明显小于粘结于牙本质的情况。粘结于牙本质的全酸蚀粘合剂体系应力下降幅度最大。粘合剂中疏水单体的存在对下降幅度有显著影响。
实验表明，流体从树脂浸渍的牙齿结构中被抽出，这可能导致牙齿 - 树脂界面出现小缺陷。
