Influence of Alloy Elements on the Osteoconductivity of Anodized Ti-29Nb-13Ta-4.6Zr Alloy

Dai Yamamoto, Atsushi Waki, Kensuke Kuroda, Ryoichi Ichino, Masazumi Okido, Masato Ueda, Masahiko Ikeda, Mitsuo Niinomi, Azusa Seki

Department of Materials Science & Engineering, Graduate School of Engineering, Nagoya University, Nagoya, Japan.
EcoTopia Science Institute, Nagoya University, Nagoya, Japan.
Faculty of Chemistry, Materials and Bioengineering, Kansai University, Suita Japan.
Hamri Co., Ltd., Tokyo, Japan.
Institute for Materials Research, Tohoku University, Sendai, Japan.

DOI: 10.4236/jbnb.2013.43028                

Abstract

Anodizing is expected to be an effective method to improve the osteoconductivity of the Ti-29Nb-13Ta-4.6Zr (TNTZ) alloy because the bioactivity of anodized Ti is good. However, it is not known how the alloy elements influence the surface roughness, composition, hydrophilicity, and osteoconductivity of the anodized film on the Ti alloy. In this study, we investigated the effects of anodizing on the surface properties and the osteoconductivity of the anodized TNTZ alloy, focusing on the functions of the individual alloy elements. The anodized oxides of the Nb, Ta, and Zr metals were hydrophobic at all the voltages applied, in contrast to the anodized oxide of Ti. As well as pure Ti, a TiO₂-based oxide film formed on TNTZ after anodizing. However, the oxide film also contained large amounts of Nb species and the molar Nb/Ti ratio in the TNTZ alloy was high, which makes the surface more hydrophobic than the anodized oxide on Ti. In vivo tests showed that the osteoconductivity of the TNTZ alloy was sensitive to both its surface roughness and hydrophilicity. When the TNTZ alloy was anodized, the process increased either the surface hydrophobicity or the surface roughness at the voltage used in this study. These changes in the surface properties did not improve its osteoconductivity.

Keywords

Ti-29Nb-13Ta-4.6Zr; Anodizing; Titanium Dioxide; Alloy Element; Hydrophilicity; Osteoconductivity

Conflicts of Interest

The authors declare no conflicts of interest.

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