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 SnO x 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 SnO x film with small spherical pores obtained at 300°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.