Abstract: Objective To make silica coating through sol-gel process, and to evaluate the wettability of dental alumina ceramic with or without coating. Methods Silica coating was prepared with colloidal silica sol on In- Ceram alumina ceramic surface which had been treated with air particle ahrasion. Coating gel af'ter heat treatment was ohserved with atomic f'orce microscopd AFM). and was analyzed by infrared spectrun( IR) with gel without sintered as control. Contact angles of' oleic acid to be f'inished, sandblasted and coated ceramic surf'ace of' were measured. Results AFM pictures showed that some parts of' nano-particles in coating gel conglomerated af'ter heat treatment. It can be seen f'rom the IR picture that bending vibration ahsorption kurtosis of' Si-OH also vanished af:ter heat treatment. Among contact angles of' three treated surface. the ones on polished surface were the biggest(P=0.000, P=O.OOO), and sandblasting+silica coating surface the smallest(P=O.OOO, P=0.003). Conclusion Silica coat-ing can be made with sol-gel process successf'ully. Heat treatment may reinforce Si-O-Si net structure of' coating gel. Wettability of' dental alumina c:eramic with silica coating is higher than with sandhlasting and polishing.

Key words: sol-gel, nano-silicacoating, aluminaceramic