Inhibitory effect of a gel paste containing surface pre-reacted glass-ionomer (S-PRG) filler on the cariogenicity of Streptococcus mutans

Surface pre-reacted glass-ionomer (S-PRG) filler is a bioactive functional glass that releases six different ions. Although several dental materials containing S-PRG filler have been developed, few self-care products containing S-PRG filler have been reported. We investigated the inhibitory effects of PRG gel paste containing S-PRG filler on Streptococcus mutans , a major pathogen of dental caries. PRG gel paste inhibited bacterial growth of S. mutans in a concentration-dependent manner, and all S. mutans were killed in the presence of ≥ 1% PRG gel paste. Additionally, it was difficult for S. mutans to synthesize insoluble glucan from sucrose in the presence of 0.1% PRG gel paste. A biofilm formation model was prepared in which slices of bovine enamel were infected with S. mutans after treatment with or without PRG gel paste. Biofilm formation was inhibited significantly more on the enamel treated with PRG gel paste than on enamel without PRG gel paste ( P < 0.001). The inhibitory effects on bacterial growth and biofilm formation were more prominent with PRG gel paste than with S-PRG-free gel paste, suggesting that PRG gel paste may be effective as a self-care product to prevent dental caries induced by S. mutans .