Surface behaviour of high MgO-containing glasses of the Si–Ca–P–Mg system in a synthetic physiological fluid

Two glasses of the Si–Ca–P–Mg system with low SiO2 content (25 and 29 mol%) and high MgO contents (31 and 36 mol%, respectively) have been immersed in a Kokubo’s synthetic physiological solution for different times up to 30 days. The surface modifications of the glasses were observed by SEM and the changes in the surface composition followed by EDS. ICP was used to assess the evolution of ionic concentrations in the solution, namely Ca and P. observed that both glasses induced the precipitation of Ca–P rich layers on their surfaces, although these were poorly attached to the glass substrate. Ca and P ions required for the apatite formation were mainly provided by the composition of the glass, which was severely dissolved in the solution. served apatite-forming ability of these glasses, notwithstanding their high MgO content, suggests that further improvements at the surface and in the glasses can lead to attractive potentially bioactive materials.