Influence of Mg doping on the early steps of physico-chemical reactivity of sol–gel derived bioactive glasses in biological medium

The aim of this study is to highlight the influence of magnesium doping on the surface reactivity of binary (SiO₂–CaO) and ternary (SiO₂–CaO–P₂O₅) bioactive glasses, prepared by sol–gel chemistry, in biological conditions. These materials were produced in powder form, and their compositional and textural properties characterized. They were then soaked in biological fluids for different delays from 0 to 4 days. The surface changes were characterized using Particles Induced X-ray Emission (PIXE) associated with Rutherford Backscattering Spectroscopy (RBS), which are efficient methods for multi-elemental analysis. Elemental maps of major and trace elements were obtained at a micrometer scale and revealed the formation of a calcium phosphate-rich layer after a few days of interaction. We demonstrate that the presence of magnesium in the material has an impact on the development and the formation rate of the bone-like apatite layer.