Antimicrobial and antibiofilm activity of silver, titanium dioxide and iron nano particles.

PURPOSE: To compare the antimicrobial effects of chlorhexidine, penicillin, erythromycin, clindamycin, tetracycline and vancomycin with silver, titanium dioxide and iron nanoparticles and also to consider the synergistic antibacterial and antibiofilm effects of nanoparticles in clinical and standard strains of Streptococcus mutans and Streptococcus sanguinis.

METHODS: The specimens collected from 66 3-5 year-old children with detected S. mutans and S. sanguinis by PCR were then exposed to the antimicrobial activity of chlorhexidine, penicillin, erythromycin, clindamycin, tetracycline and vancomycin with silver, titanium dioxide and iron nanoparticles measured by microdilution and disc diffusion tests and the colony counted after 1 to 5 minutes. The antibiofilm activity was examined by microtiter test.

RESULTS: Use of nanoparticles alone showed higher minimum inhibitory concentration (MIC) than using them synergistically. The most effective synergistic solution was the one containing TiO2, Ag and Fe3O4 showing 0.019 μg#47;ml in S. mutans and S. sanguinis. Furthermore, this solution had the lowest biofilm inhibitory concentration (BIC) and colony forming units than the other antibiotics and chlorhexidine.

CLINICAL SIGNIFICANCE: The solution containing TiO2, Ag and Fe33O4 showed the lowest inhibitory and antibiofilm concentration against S. mutans and S. sanguinis compared to those of other nanoparticle containing solutions, antibiotics and chlorhexidine, thus it may be used for treating dental caries, dental plaque and oral infections.