Fluoride Concentration, Antibacterial Effect, and Cytotoxicity in Children's Toothpaste: In Vitro Study

Abstract

Abstract Objectives The aim of this study is to evaluate the effect on cell viability, antibacterial activity against cariogenic bacteria, and total fluoride availability of commercially available children's toothpastes in Thailand. Materials and Methods Seven toothpaste slurries were prepared from seven commercial toothpastes for children. Total fluoride concentration was determined. The agar diffusion method was used to examine the antibacterial effect of toothpaste against Streptococcus mutans. The viability of L929 mouse fibroblasts exposed with different concentrations of each toothpaste slurry was tested by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay. Statistical Analysis One way analysis of variance (ANOVA) and Tukey's honestly significant difference (HSD) tests were used for zone inhibition analysis. Cell viability data were analyzed using Student's t-test. Results Fluoride concentration in fluoride-containing toothpastes ranged from 521.36 to 1,377.83 ppm. Two toothpastes exhibited a similar level of fluoride concentration compared between the product labels. Other toothpastes showed a difference or slight difference in fluoride concentration between the companies' information and our data. The zone of inhibition ranged from 0 to 2.08 cm. A significantly higher zone of inhibition was observed in toothpastes with sodium lauryl sulfate. The concentration of toothpaste that reduced cell viability to less than 50% of the control was 0.8, 3.1, 6.3, 6.3, 25, and 100% for Fluocaril Deli Fruity, Oral-B Junior 6 + , Kodomo Kids, CUdent Stevia, SunStar GUM, and Kindee Organic, respectively. Conclusion The examined children's toothpastes can inhibit the growth of S. mutans, which did not correlate with fluoride concentration. The antibacterial effects could be the results of other ingredients, for example, sodium lauryl sulfate.