The generation of hydroxyl groups on a magnesia partially stabilised zirconia (MgO-PSZ) bioceramic using CO ₂ laser treatment

For the purpose of exploring a new technique to induce OH groups on bioinert and thereby enhance their bioactivity, an industrial CO ₂ laser was used to modify the surface a magnesia partially stabilised zirconia (MgO-PSZ) bioceramic. The changes in the surface properties following CO ₂ laser irradiation were investigated. A Fourier transform infrared spectrometer (FTIR) indicated that the CO ₂ laser processing generated OH groups on the MgO-PSZ. The surface melting on the MgO-PSZ induced by CO ₂ laser processing provides the Zr ⁴⁺ ion and OH- ion and in turn, the incorporation of the Zr ⁴⁺ ion and the OH- ion creates the Zr-OH group on the surface. Initially the amount of the hydroxyl groups increased with the CO ₂ laser power density, however, there were no hydroxyl groups on the sample treated at the highest power density in the experiments. This was due to the fact that the explosive evaporation resulting from the super-high temperature on the MgO-PSZ surface treated at this power density caused water vaporization and the disappearance of the OH- band.