Hydrothermal Modification of Titanium Surfaces for Controlling Osteointegration
The combined chemical-hydrothermal synthesis of TiO2 and CaTiO3 films on pure Ti substrates was examined with a focus on film crystallinity and surface morphology. Pure Ti disks were chemically treated with H2O2/ HNO3 aqueous solutions at 353 K for 20 min in order to form a TiO2 gel layer on the surfaces. The samples were then hydrothermally treated in an autoclave at 453 K for 12 h or 24 h. Anatase-type TiO2 and perovskite-type CaTiO3 films with high crystallinity were obtained upon treatment with distilled water or aqueous NH3 and aqueous Ca(OH)2, respectively. Uniform, crack-free films were obtained. The surfaces showed excellent attachment of osteoblast-like MC3T3E1 cells in an incipient stage. Furthermore, the cells showed satisfactory proliferation, though at a slightly lower rate than on Ti. In addition, the samples were immersed in SBF (Simulated Body Fluid), adjusted to 310 K. A light hydroxyapatite (HAp) precipitate was observed on the unmodified Ti surface after 6 days of immersion. In contrast, precipitation was observed only after 2 to 4 days on the present oxide films. Thus, these oxide films are non-toxic and enhance the deposition of HAp.
T. Chandra, N. Wanderka, W. Reimers , M. Ionescu
M. Ueda et al., "Hydrothermal Modification of Titanium Surfaces for Controlling Osteointegration", Materials Science Forum, Vols. 638-642, pp. 724-729, 2010