Methods: Alumina filler, spherical in shape with diameter 23-35 µm (surface area of 0.36 m2/g), was silanized with 0.1 wt% of gamma-methacryloxypropyltrimethoxysilane (MPS). The 5, 10 and 15 wt% of silanized alumina filler were mixed with heat polymerized PMMA. Heat polymerized PMMA without alumina reinforced was served as control. All groups were prepared by packing with artificial denture teeth. Totally forty dumbbell-shaped specimens were prepared (n=10). The specimens were immersed in distilled water at 370C for 24 h prior to the test. The tensile bond strength test was performed using a universal testing machine (Instron 8872, Fareham, UK) with a 1mm/min crosshead speed until fracture. The bond strength was determined and analyzed by 1-ANOVA and Tamhane’s test with a significance level of 0.05.
Results: The mean tensile bond strengths (SD) in MPa of control, 5, 10 and15 wt% groups were 25.4 (3.1), 26.5 (4.6), 22.8 (3.8) and 18.4 (3.3), respectively. Statistical analysis suggested that the tensile bond strengths of all groups except for 15 wt% were not significantly different and in 15 wt% group was significantly small among each other.
Conclusions: Within the limitations of this study, it can be concluded that addition of silanized alumina filler reinforced into PMMA denture base less than 10 wt% do not change tensile bond strength between PMMA denture base and denture teeth.