Abstract:
The first objective of this study was to clarify the effects of silane coupling agents and different polarity solutions on bonding between poly (methylmethacrylate) (PMMA) on alumina plate with thermocyclings challenge. The second objective was to evaluate the effects of 3-methacryloxypropyltrimethoxysilane on flexural properties, fracture toughness, wear resistance and color change of alumina reinforced poly (methylmethacrylate) (PMMA) denture base. In part 1, three silane coupling agents [3-methacryloxypropyltrimethoxysilane (MPS), 3-aminopropyltriethoxysilane (APS) and N-2 (aminoethyl) 3-aminopropyltriethoxysilane (AAPS)] and 3 different polarity solutions, 70% ethanol solution, isopropanol and toluene, were selected for silanization. The shear bond strengths were statistically compared with Tukey HSD (α =0.05). The bond strengths of PMMA on the alumina before thermocyclings were greater with MPS (15.0 MPa), APS (13.8 MPa) in ethanol solution. In part 2, the 10, 30, 50 mass% of alumina filler silanized with 0, 0.1, 0.2 and 0.4 mass% of MPS was blended with heat-polymerized PMMA. PMMA without alumina filler was served as control. Bar-shaped and square-shaped specimens were prepared for flexural properties, fracture toughness and wear resistance test, respectively (n = 10). Flexural properties and fracture toughness were determined using a 3-point bending test and volume losses were measured an in-vitro 2-body wear-testing. The flexural properties, fracture toughness and volume loss were analyzed by 2-way ANOVA and Tamhane’s test (α =0.05). Flexural strength ranged from 95.1 to 115.8 MPa, fracture toughness were increase when increase amount of alumina, while volume loss ranged from 0.038 to and 0.160 mm3. In 10 mass% of alumina reinforced into PMMA, the statistic analysis showed that the 0.1 mass% of silanized group was significantly higher in flexural strength and lower in volume loss than no filler and non-silanized group. In part 3, the pink and clear PMMA silanized with 0.0, 0.1, 0.2, 0.4 mass% of MPS were evaluated the opacity and color change. The opacities value of the No filler in both of the pink and clear were significantly lower than the filler reinforced groups.
