BIOACTIVE COATINGS OF GLASS-CERAMICS ON METALS

To combine the mechanical properties of high-strength base metals with the biological properties of bioactive materials, coatings of BIOVERI T(R) glasses and glass-ceramics on CoCr alloys and titanium have been produced. Different kinds of coating processes have been used: dipping , sputtering, plasma spraying, sintering and pasting. Dipping and past ing seem not to be suitable to produce layers because of cracks and lo w adhesion strength of the coatings (dipping) and the limitations in r elation to the implant shape and the thickness of the layers (pasting) . Using sputter techniques it is possible to produce dense layers (<10 mum) with a high adhesion strength. Plasma spraying resulted in layer s with a thickness of 50 to 300 mum, but during the plasma spraying pr ocess there is a partial evaporation of the highly volatile glass comp onents. Sintering processes are very suitable to produce layers with a high adhesion strength; these layers are long-term stable in simulate d body fluid.