[Pre-treatment of porcelain surface for adhesive restorations]

The effects of pre-treatment of porcelain surfaces, such as etching and treatment with a silane coupling agent, for obtaining firm adhesion between the adhesive resin, Panavia EX, and the porcelain were examined. The effects of heating treatment (100, 150 and 200 degrees C) in applying the silane coupling agents to porcelain surfaces were examined. Infrared spectra and energy dispersive X-ray spectra were obtained for the porcelain surface, on which a silane coupling agent was applied. A stable shearing adhesive strength, such as 450-520 kgf/cm2, was obtained even after a 24-hour immersion in 37 degrees C water, when with the etching the porcelain surface was pretreated with a 30% HF solution (60 sec) or heating treatment (150 degrees C, 10 min) when applying the silane coupling agent (2% gamma-MPTS). Then the adhesive durability was examined by a thermal cycling test (4-60 degrees C, 60 sec). After the thermal cycling test (20,000 times), the adhesive strength to the porcelain surface polished by #600 sand-paper was strong and only when the 2% gamma-MPTS was used did detachment occur. However, the adhesive strength was maintained at about 70-80% of the early strength with the etching treatment by the pre-treatment with 30% HF for 60 sec and the heating treatment (150 degrees C, 10 min) when applying the 2% gamma-MPTS.