Improving the bond strength of bioactive glass coatings obtained by atmospheric plasma spraying

Abstract

Bioactive glasses are inorganic biomaterials that can provide a bioactive response and thus favor the successful bonding of orthopedic implants. Some strategies were studied to improve the bond strength of bioactive glasses, such as producing agglomerated bioactive glass powders or designing different coatings combining hydroxy apatite (HA) with bioactive glass. The bioactive coatings were produced by atmospheric plasma spray (APS) onto titanium alloy substrates, and the microstructure and adhesion strength of the developed coatings were evalu ated. It was found that a significant improvement in adhesion strength was obtained for the developed coatings, in particular when thermal treatment was applied to pure glass coatings and when HA was part of the coating. The coatings reactivity in simulated body fluid and Tris-HCl solutions was studied. All coatings showed bioactive behavior, but the ones with only an amorphous phase in the upper part of the coating dissolved faster, releasing a larger proportion of Ca ions, which caused faster nucleation and growth of apatite deposits