Silver substituted nanosized calcium deficient hydroxyapatite

Nanosized calcium deficient hydroxyapatite (CDHA) and nanosized calcium deficient hydroxyapatite with silver substitution (SCDHA) of three different silver concentrations were produced by a rapid microwave assisted synthesis method, which is a time saving and energy efficient technique. The effects of the microwave processing parameters and heat treatment on decomposition behaviour, formed phases, crystallite size and particle size and morphology of the powders were investigated. It was found that the crystallite size of the produced powder may be controlled by varying the microwave processing parameters. It was determined that the applied microwave power had a greater effect than the duration of the microwave treatment on crystallite sizes. The CDHA was found to be stable during calcinations, whereas silver addition was found to result in beta-tricalcium phosphate formation by decreasing the thermal stability of the powders. The antibacterial effect of silver substitution was investigated. The SCDHA powder showed good antibacterial activity against Escherichia coli and Staphylococcus aureus bacteria. The produced antibacterial SCDHA powder has potential usage in medical applications as a raw material for bone grafts and coating material for metallic implants. It can prevent bacterial infection without use of antibiotics, avoiding antibiotic related complications, and minimise potential risks due to bacterial infection, thus increasing patient satisfaction and decreasing hospitalisation times and medical costs.