Development of New Dental Adhesives

牙本质粘接是粘接牙科的关键技术之一，但至今仍未被广泛接受。结合结合强度和结合试样的SEM、TEM分析，探讨了结合机理。在牙本质侧粘接界面形成混杂层是树脂与牙本质粘接的关键。混合层不是牙本质，也不是树脂，而是牙本质和固化树脂的混合物。它是由分散和浸渍在牙本质中的单体聚合而形成的。单体扩散速率是单体扩散率和渗透牙本质扩散率的函数。具有疏水和亲水基团的单体可以促进单体扩散到基底中。已经开发了多种基于甲基丙烯酸酯的材料，其具有粘附牙本质的能力。本项目研究了2-（甲基丙烯酰氧基）乙基苯基磷酸氢盐（Phenyl-P）用于将甲基丙烯酸甲酯中5%的Phenyl-P键合到牙本质表面的有效性。采用部分氧化的三丁基硼烷（TBB）为催化剂，引发苯基-P/MMA单体聚合。用10%柠檬酸/3%三氯化铁水溶液预处理的牙本质与MMA中5%苯基-P的平均拉伸粘结强度为10.5MPa。扫描电镜观察证实在牙本质与树脂界面形成了混杂层。

Adhesion to dentin is a key technology in adhesive dentistry but it is not accepted well even nowadays. The bonding mechanism is discussed based on the bonding strength, and SEM and TEM examination of bonded samples. Creation of hybrid layer in dentin-side adhesive interface is essential to make bonding of resin to dentin. The hybrid layer is not dentin, not resin but a mixture of dentin and cured resin. It is formed by polymerization of diffused and impregnated monomers in dentin. The rate of monomer diffusion is the functions of diffusibility of monomers and diffusivity of penetrated dentin. Monomers with both hydrophobic and hydrophilic groups can promote diffusion of monomers into the substrate. A variety of methacrylate-based materials have been developed with the capacity of adhering to dentin. In this project, the effectiveness of 2-(methacryloyloxy)ethyl phenyl hydrogen phosphate (Phenyl-P) for bonding 5% phenyl-P in methyl methacrylate to dentinal surfaces. The polymerization of the phenyl-P/MMA monomer was initiated by partially oxidized tri-n-butyl borane catalyst(TBB). The mean tensile bond strength of 5% phenyl-P in MMA to dentin that was pre- treated with an aqueous solution of 10% citric acid/3% ferric chloride was found to be 10.5MPa. The SEM observation confirmed that the hybrid layer was formed at the interface between dentin and resin.