Surface treatment with primers containing functional monomers is a simple way to obtain high bond strength. Acidic functional monomers such as 10-methacryloyloxydecyl dihydrogen phosphate (MDP), which act on the oxide film produced on the surface of nonnoble metals, were initially used [5]. The effectiveness of MDP on titanium has been previously demonstrated [6][7][8]. Tsuchimoto et al.[9] refered to the condition of titanium surface being important for bonding using MDP. MDP and other acidic functional monomers have been known to be ineffective on noble metals, which do not produce oxide films. This problem was solved by synthesizing organic sulfur compounds that act directly on the surface of noble metals. The first organic sulfur compound to be synthesized for this purpose was 6-(4-vinylbenzyl-n-propyl) amino 1,3,5-triazine-2,4-dithiol (VBATDT) [10]. VBATDT and other organic sulfur compounds have

This study was conducted to clarify the influence of the copper surface oxidation and reduction on the shear-bond strength with functional monomers. Unheated copper specimens (UH; n = 88) were wet-ground. Three-quarters of the UH were then heated (HT). Two-thirds of the HT was then immersed in a hydrochloric acid solution (AC). Half of the AC was then reheated (RH). Each group was further divided into two groups (n = 11), which were primed by either 6-methacryloyloxyhexyl 2-thiouracil-5-carboxylate (MTU-6) or 10-methacryloyloxydecyl dihydrogen phosphate (MDP). The shear-bond strength tests were used for bonding with an acrylic resin. The surface roughness values and chemical states of the four groups were analyzed using a confocal scanning laser microscope and X-ray photoelectron spectroscopy (XPS). The shear-bond strengths of HT and RH were the lowest in the MTU-6-primed groups. The result of AC was significantly lower than others in the MDP-primed groups. The XPS results showed that the surfaces of UH and AC consisted of Cu2O and Cu. The surface changed to CuO upon heating. The presence or absence of copper-oxide films showed the opposite trends in the effectiveness of MTU-6 and MDP to improve bond strength. The results could elucidate the effects of functional monomers on copper-oxide films.

This study investigated the effect of 10-methacryloyloxydecyl dihydrogen phosphate (MDP) in methyl methacrylate (MMA) monomer on the adhesion of tri-n-butylborane (TBB)-initiated resins (MDP/MMA-TBB resins) to human enamel. Enamel surface conditions were either polished only or phosphatized surfaces. The 1.0, 1.7, and 2.0 mol% MDP/MMA-TBB resins, 4-methacryloxyethyl trimellitate anhydride (4-META)/MMA-TBB resin and MMA-TBB resin were prepared as luting materials. The shear bond strength was determined before and after thermocycles, and the results were compared using non-parametric statistical analyses (each, n=15). The MDP/MMA-TBB resins showed significantly better bond durability to enamel than other resins with or without etching. The 1.7 and 2.0 mol% MDP/MMA-TBB resins were suggested to be the optimum MDP concentrations from pre-and post-thermocycling results for the non-etched specimens. The TBB initiator resin including MDP was shown to be effective in bonding to human enamel, and this effect was enhanced in combination with phosphate treatment.

This study assessed the effect of a primer containing 10-methacryloyloxydecyl-(2-thiohydantoin-4-yl)propionate (MDTHP) on the bonding of noble metal alloys to an acrylic resin. Three noble metal alloys were selected as adherends, and V-Primer containing 6-(4-vinylbenzyl-n-propyl)amino-1,3,5-triazine-2,4-dithione was used as a comparative control. The disk specimens of each noble metal alloy were wet-ground and divided into three conditions: specimens primed with MDTHP primer or V-Primer, and specimens without priming. An acrylic resin was bonded to each specimen, and the specimens were performed the shear bond test. The MDTHP primer showed higher shear bond strength than the V-Primer for all specimens. X-ray photoelectron spectroscopic analysis showed that MDTHP was adsorbed on the Au-Pt-Pd alloy surface even after acetone cleaning. MDTHP binds not only with Cu but also with Au and Ag, promoting the bond strength of noble metal alloys. The effectiveness of MDTHP on dental noble metal alloys was suggested.