The effect of a DLC coating adhesion layer on the corrosion behavior of titanium and the Ti6Al4V alloy for dental implants

The properties of DLC layers provide for their broad use in medical applications. Their tribological properties are frequently utilized in big joint implants, and their barrier effect offers another benefit. The present work studied corrosion behavior of DLC coatings formed on titanium and Ti6Al4V alloy with a titanium or chromium inter-layer, in environments to which dental implants may be exposed. Electrochemical impedance spectroscopy, XPS surface analysis, ICP/MS chemical analysis method and a set of standard biological tests were employed in the study. havior of both coated systems, regardless of the basic material, was comparable in an environment that did not contain fluoride ions. An addition of fluorides revealed the occurrence of pores as deep as the DLC layer even in specimens with a surface polished prior to coating. Porosity of layers was clearly evident on jet-blasted specimens. The best corrosion behavior was recorded in specimens with a chromium inter-layer on both types of the basic material. With the titanium inter-layer applied, coatings on TiAlV exhibited higher corrosion resistance than those on commercial-pure titanium. The conducted biological tests indicated applicability of a chromium inter-layer on DLC coated implants.