Characterization of fluoridated hydroxyapatite/zirconia nano-composite coating deposited by a modified electrocodeposition technique

Fluoridated hydroxyapatite (FHA)/zirconia (ZrO2) nano-composite coatings were codeposited by a modified electrocodeposition technique on titanium. This nano-composite coating was fabricated by adding NaF, nano-scaled ZrO2 particles and 6% H2O2 into the electrolyte using gentle ultrasonication. The microstructure, phase composition, dissolution rate, bonding strength and in vitro cellular responses of the composite coatings were investigated. The results show that FHA and nano-scaled ZrO2 particles are relatively well distributed in the coatings, and that the addition of F− and ZrO2 reduces the crystallite size and increases the crystallinity of hydroxyapatite (HA). The approximately 5 µm thick composite coating is uniform and dense owing to the effects of H2O2 and ultrasonication. In addition, compared to pure HA coatings, the FHA/ZrO2 composite coatings show higher bonding strength, lower dissolution rate and comparable in vitro bioactivity.