Analysis of acid resistance of root surface and development of novel resin systems for prevention of root surface caries

在本研究中，通过测定脱矿临界pH值来检查根面的抗酸性，并通过体外研究来考察新型树脂涂层系统预防根面龋的有效性。结果表明：1）用酸性缓冲液进行脱矿试验，发现牙骨质在pH大于5.5时发生脱矿。约43%的样本在pH 6.3下显示脱矿，约29%在pH 6.5和6.8下显示脱矿。牙骨质比牙釉质更易受酸的影响，牙骨质开始脱矿的pH值为6.8。2）强酸蚀性的一步法粘接剂在修复后即刻和24 h与根面牙本质的粘接界面完整，而弱酸蚀性粘接剂在修复后即刻与根面牙本质发生脱粘。坚固的系统有利于从早期阶段就产生与根面牙本质的稳定粘结。3）商业单一 ...更多信息 分步自酸蚀粘接剂虽然与牙骨质有良好的粘接能力，但涂层厚度小，防止根面脱矿的效果有限。4）由自酸蚀底漆和多功能甲基丙烯酸酯组成的实验树脂涂层系统通过与牙骨质形成完整的杂交和形成中等厚度的表面涂层来防止根面酸脱矿。实验系统还显示出良好的耐久性对刷牙磨损。这些结果表明，牙骨质的脆弱性对酸是高的，预防脱矿的措施，应在暴露后的根面最早的场合进行。实验系统被证明是一个有前途的材料，应用于根面，以防止脱矿。少

In this research project, the acid resistance of root surface was examined by determining the critical pH for demineralization, and the effectiveness of novel resin-coating system for prevention of root surface caries was investigated by in vitro studies. The following results were obtained.1) By demineralization tests using acid buffer, the cementum was found to be demineralized at pH over 5.5. Approximately 43% of the specimens showed demineralization at pH 6.3, and approximately 29% at pH 6.5 and 6.8. The cementum was more vulnerable to acid compared with enamel, and the pH value at which demineralization of cementum starts was 6.8.2) The single-step adhesives with strong etching aggressiveness demonstrated integrity of the bonding interfaces to root dentin immediately and 24 h after restoration, while the mild adhesives showed de-bonding immediately after restoration. Strong systems were advantageous to produce stable bonding to root dentin from the early stage.3) Commercial single … More -step self-etching adhesives demonstrated coating with small thickness and limited effects to prevent the root surface from demineralization, although they showed good bonding ability with cementum. The commercial root dentin sealer was effective to prevent demineralization on the root surface, but its bonding ability was poor compared with adhesives.4) The experimental resin-coating system, consisting of a self-etching primer and a multi-functional methacrylate, could prevent root surfaces from acid demineralization by producing an integral hybridization with cementum and a moderately thick surface-coating. The experimental system also showed excellent durability against tooth brushing wear.These results indicate that the vulnerability of cementum to acid is high and the preventive measures against demineralization should be conducted at the earliest occasion after exposure of the root surface. The experimental system proved to be a promising material for application on root surface to protect from demineralization. Less