Anodic TiO2 nanotubes from stirred baths: hydroxyapatite growth & osteoblast responses

▶ Oxidation of Ti from stirred fluoride baths produced amorphous TiO2 nanotubes. ▶ Heat-treatment converted the amorphous coatings to mixed anatase and rutile. ▶ Heated coatings were exposed to simulated body fluid (SBF) to nucleate apatite. ▶ Ultrasonic stirring and 504 h of SBF treatment showed earlier apatite-formation. ▶ This condition also showed higher in vitro bioactivity. ▶ Increased bioactivity is attributed to fine apatite crystal size.