Zirconia coated titanium for implants and their interactions with osteoblast cells

The anodic plasma-electrochemical oxidation in aqueous electrolytes of Zr(SO4)2 was used to prepare new zirconia/titania-based surfaces M1 (Ti, Zr and O: 7-10, 22-27 and 65-69 at.%) and M2 (Ti, Zr and O: 11-13, 20-23 and 64-69 at.%). The chemical composition and the microstructure of these coatings were characterized by surface and solid state techniques such as scanning electron microscopy, electron probe microanalysis, Raman spectroscopy and X-ray diffraction. These mixed oxides of ZrO2/TiO2 surfaces consist up to 84% (m/m) of ZrO2 and 16% (m/m) of TiO2. Monoclinic zirconia was detected as the dominant microcrystalline phase. In vitro studies were conducted on primary human osteoblast cells. MTT and DAPI assays were used for assessment on cell proliferation. Immunohistochemical analyses of morphology, cell cluster formation and expression of bone sialoprotein (BSP) and osteocalcin (OC) were performed. Novel surfaces M1 and M2 induced proliferation and expression of OC and BSP similarly to Ticer, used in clinical practice. Furthermore, the presence of zirconia on titanium surface has a higher beneficial effect on the osteoblast morphological changes and cell cluster formation.