SURFACE-ANALYSIS OF BIOCOMPATIBLE COATINGS ON TITANIUM

The coatings of hydroxyapatite, which is widely used for orthopaedic a nd dental prothesis, were deposited by using the dip-coating method. T he layers of hydroxyapatite were grown on commercial Ti substrates. In order to improve the adhesion of hydroxyapatite, the substrate was a priori covered with titania or calcium titanate by using the sol-gel t echnique. For comparison, commercial samples of hydroxyapatite coating (manufactured by means of plasma-spray apparatus) were analysed. The chemical composition and the structure of the coatings (TiO2, CaTiO3 a nd hydroxyapatite) were studied by using X-ray photoelectron spectrosc opy (XPS), scanning Auger microscopy (SAM), X-ray diffraction (XRD) an d secondary electron microscopy (SEM) techniques. The data of quantita tive XPS analysis and the surface images (SAM and SEM) displayed the s uperior quality (cleanness, homogeneity, etc.) of hydroxyapatite depos ited by sol-gel in comparison with commercial samples investigated. (C ) 1998 Elsevier Science B.V. All rights reserved.