The aim of the present in vitro study is to evaluate and compare antimicrobial efficacy of commercially available child's dental formulas in reduced concentrations containing different forms of fluoride against Streptococcus mutans activity.

The selected dentifrices were prepared in dilutions of 1:1, 1:2, 1:4, 1:8, and 1:16 using sterile pyrogen-free distilled water. Various dilutions of the selected toothpaste slurries were incubated in the agar plate containing pure strains of S. mutans, and antimicrobial activity of each was assessed by measuring the diameter of zones of inhibition (in mm). Agar well plate diffusion method and minimum inhibitory concentration (MIC) determination were the methods used in this study. The inhibitory circle of each dentifrice was measured and MIC was achieved by considering the value of diameter of the circle.

The results of the study showed that even at a lower concentration of fluoride, inhibition halos were obtained for all the formulations at different dilutions.

The kid's formulations having lower fluoride concentration show antimicrobial activity even after dilutions. Thus, commercially, the fluoride concentrations can be further lowered down in the dentifrices, thereby reducing the risk associated with fluoride.

Malhotra R, Singla S, Shashikiran ND. Comparison of Antimicrobial Activity of Child Formula Dentifrices at different Concentrations: An in vitro Study. Int J Clin Pediatr Dent 2017;10(2):131-135.