Synthesis, characterization and evaluation of bioactivity of glasses in the CaO-SiO₂-P₂O₅-MgO system with different CaO/MgO ratios

Bioactive glasses (80Mg, 70Mg, 60Mg and 50Mg) in the system SiO 2 -CaO-P 2 O 5 -MgO were prepared by sol-gel method and then characterized. The structure of the synthesized samples has been studied by X-ray diffraction (XRD), Fourrier Transform Infrared Spectroscopy (FTIR) and Environmental Scanning Electron Microscopy (ESEM). In vitro bioactivity tests were performed in Simulated Body Fluid (SBF). The apparent density and wettability variation with time were measured. The in vitro studies showed the formation of an apatite-like layer covering areas of the material surface. The variation in the CaO/MgO ratio has an influence on the chemical durability and bioactivity. The XRD and FTIR analysis revealed that the samples with larger CaO/MgO ratio exhibited better bioactivity. The results showed that the 50Mg glass which has the higher content of CaO/MgO is hydrophilic sample for the two used fluids (water and SBF). The porosity and hydrophilicity increase with increased the rate of CaO/MgO. The surface of bioglasses became rougher with the increased CaO/MgO ratio, which may lead to a decrease in water contact angle.