Development of New Dental Adhesives

牙本质粘接是粘结牙科的一项关键技术，但至今仍未得到很好的接受。结合结合强度、结合样品的扫描电子显微镜和透射电子显微镜分析，探讨了结合机理。牙本质侧粘接面中杂化层的形成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。它是由牙本质中扩散和浸渍的单体聚合而成。单体扩散速率是单体扩散系数和牙本质渗透率的函数。同时具有疏水和亲水基团的单体可以促进单体向基质中的扩散。目前已开发出多种具有粘附牙本质能力的甲基丙烯酸酯类材料。在这个项目中，2-(甲基丙烯酰氧基)乙基苯基磷酸氢(Phenyl-P)将甲基丙烯酸甲酯中5%的苯基-P键合到牙本质表面。以部分氧化的三丁基硼烷(TBB)为催化剂，引发苯基-P/甲基丙烯酸甲酯(MMA)单体聚合。MMA中5%苯基-P与10%柠檬酸/3%三氯化铁水溶液处理的牙本质的平均拉伸粘结强度为10.5 Mpa。扫描电子显微镜观察证实在牙本质与树脂的界面处形成了杂化层。

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.