Chemical-Hydrothermal Synthesis of Bioinert ZrO<SUB>2</SUB>-TiO<SUB>2</SUB> Films on Pure Ti Substrates and Proliferation of Osteoblast-Like Cells

Abstract

The synthesis of bioinert oxide films on pure Ti surfaces by chemical-hydrothermal treatment was investigated. Some pure Ti substrates were chemically treated with H2O2/HNO3 to form a TiO2 gel layer prior to hydrothermal treatment. Two types of solutions in the hydrothermal treatment were prepared: Zr(OH)4 gel dispersed NH3/CH3CH(OH)COOH solution and Zr dissolved NH3/CH3CH(OH)COOH solution. A uniform layer of very fine crystals were formed on the surfaces of the specimens subjected to the hydrothermal treatment. Sharp peaks attributed to TiO2 and/or ZrO2 appeared after the hydrothermal treatment. ZrO2-TiO2 composite films were successfully produced on the Ti surface by hydrothermal treatment with the Zr(OH)4 gel dispersed NH3/CH3CH(OH)COOH solution at 453 K for 12 h, following the chemical treatment. The proliferation of osteoblast-like MC3T3-E1 cells was also investigated. The cells were observed to have spread their pseudopodiums. The cell density increased monotonically with incubation period for all specimens. The proliferation of cells was strongly influenced by the surface roughness; the cell densities increased with decreasing roughness in the range of Ra ¼ 20{80 nm. Furthermore, the surface products with TiO2 showed a relatively low rate of proliferation. The strong attachment of cells to the surface may hinder cell migration. [doi:10.2320/matertrans.MAW200910]