Surface characterization, electrochemical properties and in vitro testing of hierarchically structured titanium surfaces
Artikel i vetenskaplig tidskrift, 2013
Newly designed implant surfaces with hierarchic structure have been characterized with respect to chemical composition, topography, electrical properties and cell culturing. Three levels of surface roughness are induced starting from a blasted surface with the naturally formed oxide layer. Dissolution of the blasted surface is obtained by chemical treatment in oxalic acid. The surface becomes smoother with multitude of shallow depressions in the walls and bottoms of the blasted structure. The surface oxide layer formed is somewhat thicker than the naturally formed oxide and may contain oxalate. In the final step, part of the oxide layer is dissolved in hydrofluoric acid leading to a high concentration of soluble titanium species. A nanostructured surface is formed by precipitation of titanium oxide at spots on the surface where locally the pH is increased due to hydrogen evolution. The surface roughness is only marginally changed by the chemical treatment while the conductivity of the surface layer is lower for the chemically treated surfaces compared with the blasted reference. The hierarchical structure mimics many natural processes for achieving high shear strength. © 2012 Elsevier Ltd.
C. X-ray diffraction
Surface oxide layer
X ray diffraction
C. electron microscopy
D. electrical properties