The effect of strontium and silver on the bioactivity of a quaternary bioglass in the system SiO2-CaO-Na2O-P2O5

Bioactive glasses with 46SiO2-28CaO-20Na2O-6P2O5 (46S0), 46SiO2-28CaO-14Na2O-2SrO-4Ag2O-6P2O5 (46S2), 46SiO2-28CaO-14Na2O-4SrO-2Ag2O-6P2O5 (46S4) and 46SiO2-28CaO-14Na2O-6SrO-6P2O5 (46S6) compositions were prepared by the sol-gel method. The obtained bioglasses were sintered at 600°C for 4 hours. The structural and bioactive properties of these sintered glasses have been investigated by using X-ray diffraction, Fourier Transform Infrared Spectroscopy (FTIR). In vitro bioactivity was investigated by soaking the bioglasses in SBF for 14 and 21 days at 37°C. XRD and FTIR have shown that only the 46S0 and 46S6 bioglasses were bioactive by the formation of hydroxycarbonated apatite layer (HCA) and that bioactivity of 46S6 is better than of 46S0, however, no bioactivity have been noticed for 46S2 and 46S4 bioglasses and only AgCl has been formed after soaking in SBF as evidenced by XRD patterns. The measured wettability using a static sessile drop technique has demonstrated a high hydrophilicity for both 46S0 and 46S6 bioglasses.