title: Formation and adhesion of biomimetic hydroxyapatite deposited on titanium substrates.
abstract: This study has been carried out to investigate the bioactivity of rutile and to deposit hydroxyapatite (HA) on heat-treated titanium through a biomimetic method. Biomimetic deposition of HA has gained large interest because of its low deposition temperature and good step coverage; however, it demands a substrate with bioactive properties. Commercially pure titanium is not bioactive but it can acquire bioactive properties through various surface treatments. In the present study, titanium plates were heat-treated at 800 degrees C to achieve rutile TiO(2) surfaces. These samples were immersed in a phosphate-buffered saline solution for seven days in order to deposit a HA layer on the surface. The rutile TiO(2) surfaces were found to be highly bioactive: after seven days of immersion, a layer of HA several micrometers thick covered the plates. The HA surfaces were confirmed by electron microscopy and X-ray diffraction. A scratch test was used to assess the adhesion of the HA coatings. This is a standard method to provide a measure of the coating-to-substrate adhesion and was found to be a useful method to test the thin HA coatings deposited on the bioactive surfaces. The critical pressure of the layer was estimated to be 2.4+/-0.1GPa.
authors.affiliation: Uppsala University, The Angstrom Laboratory, Department of Engineering Sciences, Materials Science, Box 534, SE-751 21 Uppsala, Sweden.
authors.forename: Johan
authors.initials: J
authors.lastname: Forsgren
authors.forename: Fredrik
authors.initials: F
authors.lastname: Svahn
authors.forename: Tobias
authors.initials: T
authors.lastname: Jarmar
authors.forename: Håkan
authors.initials: H
authors.lastname: Engqvist
mesh_terms: D000268:Adhesiveness; D040761:Biomimetic Materials / Q000737:chemistry*; D032701:Biomimetics; D017886:Durapatite / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D014025:Titanium / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D017886:Durapatite; D014025:Titanium