Antibacterial activity of dental gels containing combinations of amine fluoride, stannous fluoride, and chlorhexidine against cariogenic bacteria.

The in vitro susceptibility of Streptococcus mutans, S. sobrinus and Lactobacillus casei to dental gels containing various combinations of amine fluoride (AmF 297), stannous fluoride (SnF2), and chlorhexidine (CHX) was studied. The combination of AmF-SnF2 with a total fluoride content of 1.2% was the most effective against mutans streptococci but not against L. casei. At notably lower total fluoride concentration (0.4%), AmF as such or combined with SnF2, was significantly less effective against mutans streptococci than CHX or CHX-AmF-SnF2 combinations. CHX-AmF combination was a slightly more potent inhibitor of streptococcal growth than CHX-NaF. With L. casei the differences between various gels were small but CHX alone seemed to be the most effective. Of the studied agents, CHX seemed to be the most potent individual chemotherapeutic compound whose activity against S. mutans could be enhanced by combining it with AmF. However, clinical experiments are required to test the in vivo antibacterial efficacy of CHX-AmF and AmF-SnF2 combinations which were most effective in our in vitro experiments.