Effect of Surface Modifications on the Bonding Strength of Titanium-Porcelain

Investigations of surface modifications on cast titanium surfaces and titanium-porcelain adhesion were performed. Cast pure titanium was subjected to surface modifications by sandblasting, preoxidation, and SnOx coating by sol-gel process. The adhesion between the titanium and porcelain was evaluated by a three-point flexure bonding test. The X-ray diffraction (XRD) and scanning electron microscopy/energy-dispersive spectroscopy (SEM/EDS) results revealed that failure of the titanium-porcelain predominantly occurred at the titanium-oxide interface after sandblasting and preoxidation treatments. The SnOx film with small spherical pores obtained at 300 degrees C served as an effective oxygen diffusion barrier and improved titanium-porcelain adhesion. With the temperature elevated, SnO was oxidized to SnO2 and the film microcracked, which resulted in the decrease of the titanium-porcelain bonding strength.