Effect of TiO 2–SiO 2 sol–gel coating on the cpTi–porcelain bond strength

Abstract

The effects of TiO 2–SiO 2 sol–gel coating with different firing temperatures (300 °C, 500 °C, and 750 °C) on the cpTi–porcelain bond strength were investigated in the present study. Prior to applying the low-fusing dental titanium porcelain, the phase, surface morphology, surface roughness and static water contact angle of the intermediate layer were evaluated. The cpTi–porcelain bond strength was measured using the three-point flexure test according to ISO 9693 standard. Statistical analyses were made using one-way ANOVA and Dunnett- t test. Significantly higher bond strength of TiO 2–SiO 2/750 °C (specimens coated with TiO 2–SiO 2 sol–gel coating and fired at 750 °C for 1 h) when compared to the control group was observed ( p < 0.05). No rutile phase was found in all the tested specimens coated with TiO 2–SiO 2 sol–gel coating. The surface morphology of the intermediate layer was apparently different with different firing temperatures. It was found that the static water contact angle of TiO 2–SiO 2/750 °C significantly decreased ( p < 0.05). However, no markedly different R a of TiO 2–SiO 2/500 °C and TiO 2–SiO 2/750 °C in comparison to that of the control group was observed ( p > 0.05). The results show that the TiO 2–SiO 2 sol–gel coating fired at 750 °C for 1 h can notably improve the cpTi–porcelain bond strength and may be suitable for clinical use.