Structure and In Vitro Bioactivity of Si Enriched Hydroxyapatite/TiO2 Coatings on Pure Titanium by Micro-Arc Oxidation

The effect of Si doping on the bioactivity and characteristics of hydroxyapatite/TiO2 composite films was investigated. Pure titanium plates were treated to form Ca, P and Si enriched titania-based films by using micro-arc oxidation (MAO). Then, some specimens were undergone a further hydrothermal treatment to produce a thin outermost layer of hydroxyapatite (HA). Experiments revealed that that the film, which was about 10μm thick, was composed of amorphous silicon dioxide, amorphous calcium phosphate, rutile and anatase. The film was porous and uneven, with the pore size of 1-4μm. No obvious cracks exist on the surface. In order to investigate the cytocompatibility of the films, periodontal ligament (PDL) cells were seeded onto the surface of the films. It was concluded that the Si ion did not influence the characters of MAO film but Si enriched hydroxyapatite/ TiO2 composite coatings exhibited an effect on cell attachment.