Abstract: A novel method was developed to grow hydroxyapatite (HA) coatings on the surface of enamel. The coatings were formed by hydrolysis of α-TCP for 6h at 37℃. The detailed characterizations of the microstructure and mechanical properties of the coatings, and cytotoxicity of α-TCP hydrolysis solution were performed. SEM and TEM analysis show that the HA coatings, approximate 20μm in thickness grow perpendicularly to the enamel surface, contacting well to the surface of enamel. Vickers microhardness and wearresistance tests indicate that there is no statistical significant difference of the hardeness and wearresistance between the coatings and healthy natural enamel. The grade of cytotoxicity of α-TCP hydrolysis solution is I grade, satisfying the relevant criterion on biomaterials. The study suggests that the hydrolysis of α-TCP is a promising method to effectively and conveniently restore and prevent early enamel caries.

Key words: α-TCP, HA, tooth enamel caries, coating