Effect of silver on the apatite formation of bioactive silicate glass

Silver (Ag) has the antibacterial property and can be easily introduced in glasses and glass-ceramics. In this research, the effect of Ag addition on the apatite formation of sol-gel derived new composition bioactive glass (BG) (55%SiO₂ - 4% P₂O₅ -22%Na₂O - (19-x) %CaO -x% Ag₂O) (x=0, 5 and 8%) were investigated. The synthesized Ag doped BG samples were treated in Hank's Balanced Salt Solution (HBSS) for 14 days to study the bioactivity. The achieved samples were evaluated by X-ray powder diffraction (XRD) and Scanning electron microscope (SEM). The XRD spectra clearly show diffraction peaks of bone-like hydroxyapatite (HAp) for all samples after immersion in HBSS. However, the more intense of HAp peak at 32° was detected in Ag(5%) and Ag(8%) BGs compared with undoped BG. All glass samples are bioactive but BG with 8 wt% of Ag₂O exhibited more apatite than the samples containing 5 wt% of Ag₂O, as seen in SEM images. After 14 days immersion, full coverage of apatite in cluster crystal form on the Ag(8) glass surface was observed.