Abstract: The corrosion mechanism of a dental glass-ceramic: fluorcanasite by oral fluid and the corrosion-resistant ability of different sol-gel derived coatings on the
glass-ceramic were investigated in vitro using SEM/EDAX, ICP and FTIR techniques. The results obtained show that the corrosion of the glass-ceramic by the oral
fluid comes of a rapid ion exchange between H₃O⁺ in the solution and Na⁺(K⁺) in the surface layer of the glass-ceramic, which results in a loose SiO₂-rich
layer on the glass-ceramic. Part of SiO₂ component dissolves into the solution in the form of Si(OH)₄ because Si-O-Si network of SiO₂-rich layer is broken
by attack of H₂O. A lot of surface defects are formed on the surface due to the corrosion of water, which decrease the strength and service life of the glass-ceramic
in an oral environment. The final reaction product on surface of the glass-ceramic is hydroxyl-carbonate apatite (HCA). Sol-gel derived Al₂O₃ coating has a
significant ability to enhance the chemical durability of the dental glass-ceramic.

Key words: sol-gel technique, glass-ceramics, artificial saliva, corrosion