Simulation of Permeability for Adhesive Monomer into Etched Dentin

研究了不同酸蚀剂处理后，甲基丙烯酸酯单体渗透牙本质与粘接强度的关系。用卤素如Br和Cl标记单体，并将用作示踪剂的卤代甲基丙烯酸酯单体加入到原始单体中。用电子探针（EPMA）分析树脂-牙本质界面上卤素、Ca、P的分布，预测各单体对酸蚀牙本质的渗透性。研究了单体中卤素、示踪剂对牙本质粘结、耐酸牙本质层形成、粘度和润湿性的影响。结果表明，单体和示踪剂中的卤素对牙本质的粘接、耐酸牙本质层的形成、粘度和润湿性无不良影响，示踪剂也能像单体一样在同一点渗入牙本质中。采用示踪剂结合电子探针的方法，对Clearfil光粘、Scotchbond和Restobond的耐酸牙本质层厚度进行了测量。EPMA测得的渗层厚度大于SEM观察的渗层厚度。Scotchbond的粘结强度较低。三种粘接剂的粘接强度与渗透性之间的关系无显著差异。

The relationship between the bond strength and the permeability of methacrylate monomers into dentin treated with various etchants was investigated. The monomers were labled with halogens such as Br and Cl, and the halogenated methacrylate monomer used as a tracer was added to the original monomer. The distribution of halogens, Ca and P at the interface between the resin and dentin was analyzed with an electron-probe microanalyzer (EPMA) in order to predict the permeability of each original monomer into the etched dentin. The effect of halogens in the monomer, and the tracer on the bonding, the formation of the acid-proof dentin layer, viscosity and wetting were investigated. It was found that the halogens in the monomer and the tracer do not adversely affect the bonding, the formation of the acid-proof dentin layer, viscosity and wetting and also the tracer can permeate into the etched ntin at same point as the original monomer does. The thickness of the acid-proof dentin layer for Clearfil photo bond, Scotchbond and Restobond was measured by means of the combination of the tracer and EPMA. The layer determined with EPMA was thicker than that observed with SEM. The bond strength of Scotchbond was lower than that of the others. There was no significant difference in relationship between the bond strength and permability for three bonding agents.