Abstract: Objective: To study the synthesis and characterization of gallium-containing hydroxyapatite coatings. Methods: Gallium-containing hydroxyapatite coatings were prepared by means of sol-gel, which were then deposited on titanium substrates with dip-withdrawal technique. The as-prepared coatings were then calcinated. Surface morphology of the coatings was tested by scanning electron microscope (SEM). The presence of functional groups for coatings was observed by X-ray diffraction spectra (XRD) and Fourier transform infrared spectroscopy spectra (FTIR). The bonding strengths of the samples were performed by pull-out test and the concentrations of Ga3+ and Ca2+ which were released from the coatings were measured by atomic absorption spectrometry (AAS). Results: Compared with HA coatings, the crystallinity of Ga-HA was higher. The concentration of released Ga3+ and Ca2+ decreased after the heat treatment to the coatings. Conclusion: The introduction of Ga increased the crystallinity but little changed the whole structure of HA coatings. The incorporation of Ga decreased the degradation of the coatings. The present study suggested the promising application of Ga-HA coatings.

Key words: Dental implants, Hydroxyapatite, Gallium, Coatings, Osteoporosis