Synergistic Effects of Antimicrobial Peptide GH12 and Fluoride on Caries

Objectives: Due to the widespread and prolonged application of fluoride, risks of fluorosis have emerged as a problem. To prevent that, it is hypothesized that with the help of perforation caused by the de novo designed and synthetic antimicrobial peptide GH12, fluoride might show an enhanced anticaires efficacy with a reduced dosage. The objective of current study was to evaluate the synergistic effects of GH12 and fluoride on S. mutans and dental caries in vitro and in vivo.
Methods: Time-kill assay was performed to verify GH12/NaF’s synergistically inhibition on growth of S. mutans. Short-term biofilm assays were adopted to evaluate the synergistic effects of GH12/NaF on biomass and cariogenic properties of S. mutans biofilm. Furthermore, in vivo Keyes scoring and S. mutans counting by quantitative polymerase chain reaction were performed using specific-pathogen-free Sprague-Dawley rats.
Results: Time-kill assay verified that GH12/NaF synergistically inhibited growth of S. mutans with fluoride. Furthermore, Short-term biofilm assays then showed that GH12/NaF synergistically reduced biomass and suppressed cariogenic properties of S. mutans biofilm. Finally, in vivo tests showed GH12/NaF combination reduced incidence and severity of dental caries and inhibited S. mutans population in rats.
Conclusions: Underlain by the molecular mechanism of GH12 and fluoride, the GH12/NaF combination exerts reciprocal synergestic effects. By use of GH12/NaF combination, the growth of S. mutans was inhibited, the biomass and cariogenicity of S. mutans biofilm was suppressed, the population of S. mutans in vivo was reduced, and thereby the onset and development of caries were arrested.