title: Bioactive macroporous titanium surface layer on titanium substrate.
abstract: A macroporous titanium surface layer is often formed on titanium and titanium alloy implants for morphological fixation of the implants to bone via bony ingrowth into the porous structure. The surface of titanium metal was recently shown to become highly bioactive by being subjected to 5.0 M-NaOH treatment at 60 degrees C for 24 h and subsequent heat treatment at 600 degrees C for 1 h. In the present study, the NaOH and heat treatments were applied to a macroporous titanium surface layer formed on titanium substrate by a plasma spraying method. The NaOH and heat treatments produced an uniform amorphous sodium titanate layer on the surface of the porous titanium. The sodium titanate induced a bonelike apatite formation in simulated body fluid at an early soaking period, whereby the apatite layer grew uniformly along the surface and cross-sectional macrotextures of the porous titanium. This indicates that the NaOH and heat treatments lead to a bioactive macroporous titanium surface layer on titanium substrate. Such a bioactive macroporous layer on an implant is expected not only to enhance bony ingrowth into the porous structure, but also to provide a chemical integration with bone via apatite formation on its surface in the body.
authors.affiliation: Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan. kim@sung7.kuic.kyoto-u.ac.jp
authors.forename: H M
authors.initials: HM
authors.lastname: Kim
authors.forename: T
authors.initials: T
authors.lastname: Kokubo
authors.forename: S
authors.initials: S
authors.lastname: Fujibayashi
authors.forename: S
authors.initials: S
authors.lastname: Nishiguchi
authors.forename: T
authors.initials: T
authors.lastname: Nakamura
mesh_terms: D001031:Apatites / Q000737:chemistry; D001826:Body Fluids / Q000737:chemistry; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D006358:Hot Temperature; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D016062:Porosity; D019736:Prostheses and Implants; D012972:Sodium Hydroxide / Q000737:chemistry; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: D001031:Apatites; D020099:Coated Materials, Biocompatible; D012972:Sodium Hydroxide; D014025:Titanium