title: Surface modification of a Ti-7.5Mo alloy using NaOH treatment and Bioglass coating.
abstract: The objective of this study was to propose a surface modification for a low-modulus Ti-7.5Mo alloy to initiate the formation of hydroxyapatite (HA) during in vitro bioactivity tests in simulated body fluid (SBF). Specimens of commercially pure titanium (c.p. Ti) and Ti-7.5Mo were initially immersed in a 15 M NaOH solution at 60 degrees C for 24 h, resulting in the formation of a porous network structure composed of sodium titanate (Na(2)Ti(5)O(11)). Afterwards, bioactive Bioglass particles were deposited on the surface of NaOH-treated c.p. Ti and Ti-7.5Mo. The specimens were then immersed in SBF at 37 degrees C for 1, 7 and 28 days, respectively. The apatite-forming ability of the NaOH-treated and Bioglass-coated Ti-7.5Mo was higher than that of the c.p. Ti under the same condition. The X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDS) results indicated that the deposited amounts of calcium phosphate were much greater for the surface-treated Ti-7.5Mo than for the c.p. Ti, a finding attributable to or correlated with the higher pH value of the SBF containing surface-treated Ti-7.5Mo. Moreover, in the surface-treated Ti-7.5Mo, the pH value of the SBF approached a peak of 7.66 on the first day. A combination of NaOH treatment and subsequent Bioglass coating was successfully used to initiate in vitro HA formation in the surface of the Ti-7.5Mo alloy.
authors.affiliation: Department of Materials Science and Engineering, Da-Yeh University, 168 University Road, Dacun, Changhua, 51591, Taiwan, ROC. fujii@mail.dyu.edu.tw
authors.forename: Wen-Fu
authors.initials: WF
authors.lastname: Ho
authors.forename: Chien-Hung
authors.initials: CH
authors.lastname: Lai
authors.forename: Hsueh-Chuan
authors.initials: HC
authors.lastname: Hsu
authors.forename: Shih-Ching
authors.initials: SC
authors.lastname: Wu
mesh_terms: D000497:Alloys / Q000032:analysis / Q000737:chemistry*; D001031:Apatites / Q000032:analysis / Q000737:chemistry; D001826:Body Fluids / Q000737:chemistry; D002130:Calcium Phosphates / Q000032:analysis; D002516:Ceramics; D017886:Durapatite / Q000032:analysis / Q000737:chemistry; D010087:Oxides; D013052:Spectrometry, X-Ray Emission; D014025:Titanium / Q000032:analysis / Q000737:chemistry*; D014961:X-Ray Diffraction; D014965:X-Rays
chemical_list: D000497:Alloys; D001031:Apatites; C022107:Bioglass; D002130:Calcium Phosphates; D010087:Oxides; C471701:sodium titanate; D017886:Durapatite; C020243:calcium phosphate; D014025:Titanium