The surface morphology of TiN-coated nanotubular Ti-25Ta-xZr alloys prepared by radio-frequency sputtering for dental implants was investigated. Ti-25Ta-(0-15 wt.%) Zr alloys were initially formed in an arc-melting vacuum furnace, homogenized for 12 h at 1000 degrees C, and water-quenched. Formation of a nanotubular structure was achieved on the alloys by anodization at room temperature in 1 MH3PO4 electrolytes containing 0.8 wt.% NaF. A TiN coating was then placed on the alloys using a radio-frequency magnetron sputtering technique. These depositions were performed on the alloy substrates using pure Ti targets. Surface morphologies of the nanotubular alloys were examined by a variety of instruments. The nanotube diameters on Ti-25Ta, Ti-25Ta-3Zr and Ti-25Ta-7Zr had irregular distribution, while the nanotubes on Ti-25Ta-15Zr had a more regular pattern of large tubes surrounded by several smaller tubes. As the Zr content in these alloys increased, the average thickness of the TiO2 nanotubes increased. At high Zr content, the surface of the nanotubes was covered with the TiN film. The Zr content affects the R-a and wettability, providing a hydrophilic property. (C) 2013 Elsevier B. V. All rights reserved.