Material properties and antibacterial activity of carbonate apatite cement prepared with silver-containing vaterite powder

In this study, silver-containing carbonate apatite (CO₃Ap) cement was prepared by mixing silver-containing vaterite and calcium hydrogen phosphate (DCPA) powder in an aqueous phosphate solution. The material properties and antibacterial performance of the cement were evaluated. Silver ions were introduced during vaterite synthesis, resulting in a composite CO₃Ap cement containing silver phosphate (Ag₃PO₄). The addition of silver nitrate did not affect key physical properties of the cement, including strength and porosity. Antibacterial testing using inhibition zone measurements confirmed that effective antibacterial activity was achieved even at low silver contents. At high silver concentrations, the coexistence of amorphous nanoclusters and Ag₃PO₄ is expected to form a biphasic release system that enables both immediate and sustained silver ion release. These results demonstrate that introducing silver ions during vaterite synthesis is an effective approach for producing antibacterial CO₃Ap cement with strong potential for orthopedic and dental applications.