Formulation of different concentrations of nanosilver fluoride incorporated dentifrices, evaluation of its cytotoxicity and antimicrobial effect on Streptococcus mutans
Authors: Gupta Nidhi , Yadav Mamta , Gambhir Natasha , Singh Divya 
Published: January 2025

ABSTRACT

Background:
Dental caries is a prevalent oral health issue primarily caused by Streptococcus mutans, a bacterium that contributes to tooth decay. Antimicrobial agents in dentifrices are often utilized to target these pathogens. Nano silver fluoride (NSF) has emerged as a potential antimicrobial agent due to its ability to inhibit bacterial growth. This study aims to investigate the antimicrobial efficacy and cytotoxicity of dentifrices containing varying concentrations of NSF against Streptococcus mutans.

Aim:
The primary aim of this study was to evaluate the antimicrobial effectiveness of Nano silver fluoride-incorporated dentifrices against Streptococcus mutans and assess their cytotoxic effects on mammalian cells.

Objectives:
To synthesize and characterize nano silver particles using transmission electron microscopy (TEM).To determine the antimicrobial activity of NSF dentifrices at different concentrations using the agar well diffusion method. To assess the cytotoxicity of NSF dentifrices on RAW 264.7 mouse macrophage cells using the MTT assay.

Material and Method:
Synthesis and Characterization: Nano silver particles were synthesized through a chemical reduction process, resulting in particles with sizes ranging between 40-50 nm, confirmed via TEM analysis. Preparation of Dentifrice: Various concentrations of Nano silver fluoride (0%, 0.65%, 1.25%, 2.5%, and 5%) were incorporated into a dentifrice base. Antimicrobial Testing: The antimicrobial efficacy of the NSF dentifrices was assessed using the agar well diffusion method, where the zone of inhibition around each well was measured to evaluate bacterial growth suppression. Cytotoxicity Assessment: Cytotoxicity was analyzed using the MTT assay on RAW 264.7 mouse macrophage cells, with NSF concentrations ranging from 0.156% to 10% to determine their impact on cell viability.

Results:
The study demonstrated that dentifrices containing NSF showed significant antimicrobial activity against Streptococcus mutans, with a dose-dependent increase in the zone of inhibition. Higher concentrations of NSF were associated with larger zones of bacterial inhibition. A one-way ANOVA revealed statistically significant differences between various concentrations, with post hoc Bonferroni tests confirming significant differences between specific pairs. In terms of cytotoxicity, a dose-dependent decrease in cell viability was observed with increasing concentrations of NSF. The lowest concentration (0.156% NSF) had the highest cell viability (86.67%), while the highest concentration tested (10% NSF) resulted in minimal cell viability (0.68%).

Conclusion:
The study concludes that NSF-incorporated dentifrices exhibit promising antimicrobial efficacy against Streptococcus mutans in a concentration-dependent manner. However, increasing concentrations of NSF also correlated with higher cytotoxicity levels in mammalian cells. Therefore, optimizing the concentration of NSF in dentifrices is crucial to balance antimicrobial benefits with biocompatibility.