Surface treatment of titanium by a polydimethylsiloxane coating on bond strength of resin to titanium.

To evaluate the in vitro effect of titanium surface treatment by a polydimethylsiloxane coating on the shear bond strength of a resin composite cement to titanium. The titanium samples (40×30mm) were divided into 4 groups (n=12). A control group was surface treated by sandblasting using 110µm silica-coated alumina powder at a constant pressure of 300kPa for 15s/1cm(2). For other three test groups, a polydimethylsiloxane silicone grease was applied onto the surface. The samples were subjected to thermal treatment in air at temperatures of 800°C, 1000°C, and 1100°C for 2h. A silane coupling agent was then applied and a resin composite stub was bonded using a polyethylene mold. The samples were submitted to three different storage conditions: dry storage, water storage in deionized water at 37°C for 30 days and thermo-cycled for 6000 cycles between 5.0 and 55.0°C. The shear bond strengths of all test groups were determined using a universal testing machine. Data were analyzed by two-way ANOVA and Tukey HSD (p<0.05). The surface morphology of titanium and elemental composition were examined with SEM and EDAX. The results showed that there was a significant difference for different surface treatments (p<0.001) and different storage conditions (p<0.01) on the mean shear bond strengths. EDAX analysis showed there was a change of elemental composition of titanium surface after thermal treatment of the coating. Surface treatment of titanium with a polydimethylsiloxane coating at 1000°C and 1100°C curing provides sufficient resin bonding for clinical services.