One-year water-ageing of calcium phosphate composite containing nano-silver and quaternary ammonium to inhibit biofilms

Research Summary

Caries prevention: Antibacterial additives in dental restoration

Antibacterial properties of dental restorations improve on addition of nano-silver and an ammonium compound. Amorphous calcium phosphate is widely used for restoration because of its biocompatibility and similar composition to minerals in hard tissues. However, the detrimental formation of biofilms on dental resins and hence, the promotion of secondary caries, are problems. Hockin Xu at the University of Maryland, US, and Xuedong Zhou at Sichuan University, China, monitored the mechanical and antibacterial properties of a range of calcium phosphate composites to assess the effects of adding nano-silver and quaternary ammonium dimethylacrylate. Both additives decreased the formation of biofilms as well as lactic acid production over one year. Moreover, composites that incorporated both additives showed significantly enhanced antibacterial properties compared to those with a single additive. The composites’ mechanical properties were not compromised by additive incorporation.