title: Preparation of bioactive Ti metal surface enriched with calcium ions by chemical treatment.
abstract: A calcium solution treatment was applied to a NaOH-treated titanium metal to give it bioactivity, scratch resistance and moisture resistance. The titanium metal was soaked in a 5 M NaOH solution and then a 100 mM CaCl(2) solution to incorporate Ca(2+) ions into the titanium metal surface by ion exchange. This treated titanium metal was subsequently heated at 600 degrees C and soaked in hot water at 80 degrees C. The NaOH treatment incorporated approximately 5 at.% Na(+) ions into the Ti metal surface. These Na(+) ions were completely replaced by Ca(2+) ions by the CaCl(2) treatment. The number of Ca(2+) ions remained even after subsequent heat and water treatments. Although the NaOH-CaCl(2)-treated titanium metal showed slightly higher apatite-forming ability in a simulated body fluid than the NaOH-treated titanium metal, it lost its apatite-forming ability during the heat treatment. However, subsequent water or autoclave treatment restored the apatite-forming ability of the NaOH-CaCl(2)-heat-treated titanium metal. Although the apatite-forming ability of the NaOH-heat-treated titanium metal decreased dramatically when it was kept at high humidity, that of NaOH-CaCl(2)-heat-water-treated titanium metal was maintained even in the humid environment. The heat treatment increased the critical scratch resistance of the surface layer of the NaOH-CaCl(2)-treated titanium metal remarkably, and it did not deteriorate on subsequent water treatment.
authors.affiliation: Department of Biomedical Sciences, College of Life and Health Sciences, Chubu University, Kasugai, Aichi, Japan. t-kizuki@isc.chubu.ac.jp
authors.forename: Takashi
authors.initials: T
authors.lastname: Kizuki
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Takadama
authors.forename: Tomiharu
authors.initials: T
authors.lastname: Matsushita
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakamura
authors.forename: Tadashi
authors.initials: T
authors.lastname: Kokubo
mesh_terms: D002118:Calcium / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: D014025:Titanium; D002118:Calcium