Plasma Spraying of Silica Modified Hydroxyapatite Coatings

Abstract: Hydroxyapatite (HA) was preferred for its ability to interact with living bone, resulting in improvements of implant fixation and faster bone healing. HA coatings have been widely investigated for application on surface of biomedical metals to improve bonding and interaction between body tissues and implant. In this study, a small amount of amorphous silicon dioxide (~ 2wt. %) was introduced into HA slurry which was subsequently spray-dried into powder. A silicon modified HA coating was then deposited onto Ti-6Al-4V alloy substrates by atmospheric plasma spraying technology. Scanning electron microscopy (SEM), X-ray diffraction and X-ray photoelctron spectrometry, and Raman spectrometry were employed to investigate the surface chemistry that would directly influence bone forming cell proliferation. Additionally, the adhesive bonding strength of the as-sprayed coatings were specified using a universal testing system. Cell culture work showed that the osteoblast cells could survive and proliferate on these silica modified HA coating, the tensile results indicated the presence of silica showed side effects on the adhesion strength of plasma sprayed coatings due to its porous microstructure.