The structure and in vitro apatite formation ability of porous titanium covered bioactive microarc oxidized TiO2-based coatings containing Si, Na and Ca

The microarc oxidation (MAO) was used to prepare TiO2 based coating containing Si, Ca and Na elements (SCN) on porous titanium sintered with different sizes of titanium beads. The chemical states of elements and apatite-forming ability of MAO coatings were investigated. The effect of titanium beads diameter on the chemical states of Ca and Si of MAO coatings on the surfaces of porous titanium is not obvious. However, the chemical states of Ti and O changed when the titanium beads diameter increased. The current results reveal that the MAO coatings containing SCN elements have good induction capability for the heterogeneous nucleation and growth of apatite in a simulated body fluid (SBF). The appropriate size of titanium beads could promote the apatite formation on porous titanium with MAO coatings. The reason for this is that the appropriate size of titanium beads can be helpful to introduce more amounts of SCN elements into MAO coatings on the porous titanium.