The purpose of this study was to investigate the changes of the nanostructured surface of Ti-35Ta-xZr alloys for dental application resulting from changes in anodization factors. TiO(2) nanotubes were formed on Ti-35Ta-xZr alloys by anodization in H(3)PO(4)-containing NaF solutions. Anodization was carried out using a scanning potentiostat. Microstructures of the alloys were examined by optical microscopy (OM), field emission scanning electron microscopy (FE-SEM) and x-ray diffraction (XRD). Microstructures of the Ti-35Ta-xZr alloys were changed from alpha '' phase to beta phase, and morphologies changed from a needle-like to an equiaxed structure, with increasing Zr content. As the Zr content increased from 3 to 7 to 15 wt.%, the average thickness of the TiO(2) nanotubes increased from 4.5 mu m to 6.1 mu m to 9.0 mu m. When the anodizing potential was increased from 3 V to 10 V, the thickness of the nanotube layers increased from about 0.5 mu m to 9.5 mu m. As the anodization time increased from 30 min to 180 min at 10 V, the nanotube thickness increased from 4 mu m to 9.5 mu m. The amorphous oxide phase in the nanotubes transformed to anatase and rutile phases of TiO(2) by heat treatment above 300 degrees C. (C) 2011 Elsevier B.V. All rights reserved.