Preparation and characterization of porous Ag doped hydroxyapatite bioceramic scaffolds

Silver doped hydroxyapatite (HAp–Ag) containing different amounts of Ag (0.5 wt% and 0.8 wt%) was prepared using wet chemical precipitation method. In the synthesis process CaO, H3PO4 and AgNO3 were used as raw materials. Porous HAp and HAp–Ag scaffolds via viscous mass foaming technique were prepared from as-synthesized powders and obtained samples were sintered at different temperatures. According to the XRD data and SEM microstructure analysis, silver ions from HAp–Ag structure were excluded and additional silver phase during the sintering process was formed. Impact of sintering temperature (1000 °C and 1200 °C) on the porosity, density, specific surface area and mechanical properties of porous HAp and HAp–Ag scaffolds was evaluated. Total porosity of 71% (at 1000 °C) and 54% (at 1200 °C) was achieved. Incorporation of Ag into the HAp structure resulted in the decrease of porous scaffold compressive strength by 30–50% compared to pure HAp porous scaffolds. Increasing the sintering temperature of porous scaffolds up to 1200 °C, it was possible to obtain samples with 2–4 times higher compressive strength, compared to samples sintered at 1000 °C.