Zirconia ceramics used for dental implants have low bioactivity. Their surface roughness needs to be enhanced for improved bone-bonding ability and cell adhesion. Zirconia implants in the gums with low surface roughness have a probability detachment over time. In this study, a zirconia substrate zirconia was coated by a powder via spray processing at room temperature (25 ^oC) to increase its surface roughness. In addition, we investigated the morphology of the as-produced rough substrate, including microstructural evolution. Four types of zirconia substrates with different surface texture were fabricated via surface-grinding by silicon carbide (SiC) abrasive papers (#220, #400, #800) after sintering. Room temperature spray processing was carried out using a commercial zirconia powder after thermal treatment. The as-produced zirconia coatings showed dense microstructure and uniform thickness. Surface roughness of zirconia substrate was greatly enhanced depending on the surface texture of the substrate. Surface texture by substrate grinding affected coating morphology; however, it did not increase the surface roughness of the substrate or the coatings. High-roughened coatings and thick coating layer could be obtained from the as-sintered substrate owing to its high surface roughness.

Keywords: Zirconia substrate, Room temperature spray processing, Surface roughness