Study on a novel antibacterial light-cured resin composite containing nano-MgO.

A new type of photocurable resin composite containing nano-MgO was synthesized in order to reduce the occurrence of secondary caries. Different mass ratios (0 %, 1 %, 2 %, 4 %, 8 %) of nano-MgO were added into resin composites. The antibacterial properties of nano-MgO powder and modified resin composites against Streptococcus mutans (S. mutans) were detected by antibacterial ring test and film contact test, respectively. Compressive strength (CS) and wear resistance were determined by a universal testing machine and an abrasion test machine. The results indicated that antibacterial activity and wear resistance of resin composites containing nano-MgO were superior to the control group (p < 0.05). The antibacterial rate reached as high as 99.4 % when the mass ratio of nano-MgO was 8 %. However, the CS values tended to decline as the content of nano-MgO increase. Hence, the addition of nano-MgO showed excellent antibacterial property to resin composites and enhanced wear resistance, but was detrimental to their mechanical properties.