Investigation of fabricating enamel-like structure in vitro is of great interest in the fields of dentistry and material sciences. In this study the coatings with organized fluoridated hydroxyapatite crystals were obtained on etched human enamel (14 oC- 45 oC) using a simple chemical approach. In the chemical approach phosphoric acid etched enamel slices were immersed in a solution for 10 days which contained NaH2PO4, Ca(NO3)2, EDTA-Na2 and NaF to form fluoridated hydroxyapatite coatings. The coating was analyzed by SEM, EDS, XRD, FT-IR and nanoindentation tests. We found that the coating is uniform and dense, with enamel-like structure and the crystals of coating have a typical hexagonal structure and are about 200 nm in cross section and the shape of crystal. When the enamel slices were immersed for 10 days the Elastic modulus and hardness of the coating reached 85.3 ± 6.2 GPa and 3.91 ± 0.55 GPa respectively which are close to that of natural enamel. Compared to hydroxyapatite (HAP) coatings it is useful and demonstrates a potential application to repair enamel damage in dental clinics.

Keywords: FAP, Enamel, Chemical deposition, Coating, Hexagonal structure