Evaluation of the Antibacterial Effects of Nickel Nanoparticles on Biofilm Production by Streptococcus mutans

Dental caries is a biofilm-dependent disease mainly causes by cariogenic bacteria that
colonize dental surfaces, especially Streptococcus mutans. Nickel is a safe metal element which
routinely used in dental compounds. The antibacterial and anti-biofilm effects of nickel nanoparticles
(Ni-NPs) have been determined in limited studies, but the anti-biofilm effects of Ni-Nps on S. mutans
have not been investigated before, so this study was aimed to investigate the anti-biofilm effects of NiNPs on S. mutans ATCC 35668.
Methods: Biofilm formation by S. mutans ATCC 35668 was assayed by Microtiter Dish Biofilm
Formation Assay and absorbance was measured by ELISA reader at 550 nm. The amounts of biofilm
formation were also measured in the presence of 1, 01 and 0.01mg/mL concentrations of Ni- NPs by
the same protocol and the mean amounts were compared between groups. Eight replicates were
considered for each experiment. Data was statistically analyzed by SPSS16 software.
Results: According to the statistical analysis, the amounts of biofilm formation were significantly
reduced in the presence of all the tested concentrations of Ni-NPs.
Conclusion: The current findings showed the potent anti-biofilm effects of Ni-NPs even in a
concentration as low as 0.01 mg/ mL, so it is proposed for different applications in dentistry, considering
its anti-biofilm effects. However, further studies on other biofilm producing members of oral microbiota
including Lactobacilli are recommended