Abstract
This study evaluated the water resistance of resin composites. The filler surface of these composites was treated with a new hydrophobic silane coupling agent. The new silane coupling agent 3-(3-methoxy-4-methacryloyloxyphenyl) propyltrimethoxysilane (p-MBS) contains a hydrophobic phenyl group. Experimental light-cure hybrid composites were formulated which contain 85 wt% of fillers treated with this silane. Composites containing fillers treated with 3-methacryloyloxypropyltrimethoxysilane (3-MPS) was also produced. Three experimental composites, p-MBS, 3-MPS and one commercial composite, Clearfil AP-X (Kuraray Medical Co.), were subjected to the tensile test. 10 specimens per group were prepared for the tensile test, and then the specimens were stored in room temperature air for 1 day before being finally thermal stressed for 30,000 cycles. The collected data were analyzed statistically using the one-way ANOVA and Tukey multiple comparison test as the post-hoc test. Tensile strength of the composites containing filler treated with p-MBS (71.6 MPa) was significantly higher compared with the composites containing filler modified with 3-MPS alone (27.1 MPa) or the commercial composite (AP-X = 52.6 MPa) after thermal cycling (p<0.05). The tensile strengths of the p-MBS composite was not also significantly lower after thermal stressed. The resin composites containing fillers treated with the novel hydrophobic silane showed superior water resistance. The reason might be that the coupling layers of this silane may have a high affinity with the base resin and increased hydrophobic properties, too.
