Anticorrosive ZrO2 and ZrO2-SiO2 layers on titanium substrates for biomedical applications

The aim of the presented study was to evaluate the potential of ceramic coating to reduce titanium susceptibility to corrosion. Ceramic coatings composed of zirconia and zirconia-silica were investigated. To examine the surface morphology of the samples, the investigation under Scanning Electron Microscope and Confocal Microscope was performed and the coatings with the lowest amount of cracks were chosen for further evaluation, involving wettability and Surface Free Energy studies. Furthermore, measurement of the corrosion resistance of the obtained samples was done via polarization technique, ran in a 3-electrode set-up. The impact on cells' morphology, cells' viability and cytotoxicity were investigated in vitro using Normal Human Osteoblasts. Finally, the stability of the obtained coatings was studied by immersing and incubating the samples in different solutions of artificial saliva (with a varying value of pH) and investigating the coatings' susceptibility to cracking by SEM and confocal microscopy. Both types of coating have been proven to decrease the susceptibility to corrosion of titanium materials. Single zirconia-silica layer present better corrosion protection than single zirconia layer. Biological research carried out as part of our experiment revealed that the zirconia-silica layer does not compromise titanium biocompatibility. In summarize single zirconia-silica layer protect titanium implant from corrosion processes while the lack of the negative influence on osteoblast multiplication.