The adhesion between dental porcelain and titanium coated with silica using the sol-gel dip coating technique

The oxidation characteristic of titanium is considered to be the main problem in bonding it to dental porcelain because of the excessive oxidation layer occurred at the stage of titanium preparation and porcelain fi ring. The previous study showed that coating titanium surface with some materials could control the titanium oxide formation at elevated temperatures and generate a new adherent oxide layer. This study was conducted to determine the adhesion between dental porcelain and titanium coated with silica using the sol-gel dip coating technique. Thirty titanium-porcelain specimens were fabricated for four-point bending test and divided into three groups, ten specimens for each group for different preparation conditions. The specimens were prepared under argon rich atmosphere. A notch was made on the porcelain side and a pre-crack was created at titanium-porcelain interface. The pre-cracked specimens were subjected to four-point bending test on the universal testing machine. The interfacial fracture toughness was determined in terms of strain energy release rate (G value). The results showed that the adhesion between porcelain and titanium of the group that titanium was coated with silica combined with VITA Titankeramik bonder application and the group that titanium was applied with VITA Titankeramik bonder are signifi cantly higher than that of the group that titanium was coated with silica only (p < 0.001).