The influence of surface conditions and silane agents on the bond of resin to dental porcelain.

The influence of porcelain surface condition and the application of silane agents on the adhesion between resin and dental porcelain were investigated. The experimental variables included three porcelain surface preparations, as polished, etched with phosphoric acid, or etched with hydrofluoric acid and three kinds of commercially available silane coupling agents. The shear bond strength between the light-cured composite and the dental porcelain was measured after one-day immersion in 37 degrees C water. Samples without the silane agent application were also tested as controls. Without the silane agent, hydrofluoric acid-etched specimens had a higher bond strength than polished or phosphoric acid-etched specimens. The combination of hydrofluoric acid-etching and an application of Cosmotech Porcelain Primer increased the bond strengths more than that of phosphoric acid-etching. With the application of Laminabond Porcelain Primer or Optec Silane Coupling Agent, high bond strengths were obtained regardless of the porcelain surface condition. Therefore, it seems the chemical reactions between the porcelain surface and silane agents were responsible for the high shear bond strengths.