title: Effect of surface modification on the photocatalysis of Ti-Ni alloy in orthodontics.
abstract: Photocatalytic activity from the reaction of titanium oxide with ultraviolet light has recently gained much attention. In particular, there is scientific interest in inducing photocatalytic reactions on Ti-Ni alloy, a material widely used in orthodontic applications. However, it is believed that inducing a photocatalytic reaction with an amorphous oxide film on the alloy is a difficult challenge. In this study, therefore, we sought to induce a photocatalytic reaction on Ti-Ni alloy by subjecting the latter to electrolytic and heat treatments. Then, an antibacterial test was used to examine whether a photocatalytic reaction had indeed been induced. By thickening the titanium oxide film with electrolytic treatment and then applying heat treatment, the surface oxide film of Ti-Ni alloy was thus modified from amorphous structure to rutile crystal. Furthermore, it was revealed that Ti-Ni alloy had an antibacterial effect by virtue of the photocatalytic reaction.
authors.affiliation: Orthodontic Science, Graduate School, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan. holy.orts@tmd.ac.jp
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Horiuchi
authors.forename: Mariko
authors.initials: M
authors.lastname: Horiuchi
authors.forename: Takao
authors.initials: T
authors.lastname: Hanawa
authors.forename: Kunimichi
authors.initials: K
authors.lastname: Soma
mesh_terms: D000891:Anti-Infective Agents, Local / Q000494:pharmacology; D002384:Catalysis; D020099:Coated Materials, Biocompatible; D015169:Colony Count, Microbial; D018360:Crystallography, X-Ray; D004572:Electrolysis; D004926:Escherichia coli / Q000187:drug effects*; D006358:Hot Temperature; D008422:Materials Testing; D009532:Nickel / Q000737:chemistry* / Q000494:pharmacology* / Q000528:radiation effects; D016382:Orthodontic Appliance Design; D010777:Photochemistry; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry* / Q000494:pharmacology* / Q000528:radiation effects; D014466:Ultraviolet Rays
chemical_list: D000891:Anti-Infective Agents, Local; D020099:Coated Materials, Biocompatible; C040654:titanium nickelide; C009495:titanium dioxide; D009532:Nickel; D014025:Titanium