Effects of CO2 laser irradiation on the surface properties of magnesia-partially stabilised zirconia (MgO-PSZ) bioceramic and the subsequent improvements in human osteoblast cell adhesion

In order to acquire the surface properties favouring osseointegration at the implant and bone interface, human foetal osteoblast cells (hFOB) were used in an in vitro test to examine changes in cell adhesion on a magnesia-partially stabilised zirconia (MgO-PSZ) bioceramic after CO2 laser treatment. The surface roughness, microstructure, crystal size and surface energy of untreated and CO2 laser-treated MgO-PSZ were fully characterised. The in vitro cell evaluation revealed a more favourable cell response on the CO2 laser-treated MgO-PSZ than on the untreated sample. After 24-h cell incubation, no cell was observed on the MgO-PSZ, whereas a few cells attached on the CO2 laser-treated MgO-PSZ and showed well spread and good attachment. Moreover, the cell coverage density indicating cell proliferation generally increases with CO2 laser power densities applied in the experiments. The enhancement of the surface energy of the MgO-PSZ, especially its polar component caused by the CO2 laser treatment, was found to play a significant role in the initial cell attaching, thus enhancing the cell growth. Moreover, the change in topography induced by the CO2 laser treatment was identified as one of the factors influencing the hFOB cell response.