A novel high-strength GIC system with long-lasting antibacterial function

Objectives: The objective of this study was to synthesize poly(quaternary ammonium salt) (PQAS)-containing polymers, use them to formulate the light-curable glass-ionomer cements and study the effect of the PQAS on the compressive strength and antibacterial activity of the formed cements. Methods: The functional QAS and their constructed PQAS were synthesized, characterized and formulated into the experimental cements. Compressive strength (CS) and S. mutans viability were used to evaluate the mechanical strength and antibacterial activity of the cements. Fuji II LC cement was used as control. The specimens were conditioned in distilled water at 37 oC for 24 h prior to testing. The effects of the chain length, loading as well as grafting ratio of the QAS and aging on CS and S. mutans viability were investigated. Results: All the PQAS-containing cements showed a significant antibacterial activity, accompanying with an initial CS reduction. Increasing chain length, loading, grafting ratio significantly enhanced antibacterial activity but reduced the initial CS. The experimental cement showed less CS reduction and higher antibacterial activity than Fuji II LC. The long-term aging study indicates that the cements may have long-lasting antibacterial function. Conclusions: Within the limitations of this study, it appears that the experimental cement is a clinically attractive dental restorative that can be potentially used for long-lasting restorations due to its high mechanical strength and long-lasting antibacterial function. This work was sponsored by NIH challenge grant (RC1) DE020614.