Antimicrobial Efficacy of Mixtures of Nanosilver and Zinc Oxide Eugenol against Enterococcus faecalis

This study aimed to assess the antimicrobial efficacy of 0, 0.5, 2, and 5 wt% nanosilver in conjunction with zinc oxide eugenol (ZOE) against Enterococcus faecalis.

Nanosilver in 0.5, 2, and 5 wt% concentrations was added to ZOE and the antibacterial activity of the mixtures on E. faecalis was assessed using disk diffusion method, and the results were reported as the diameter of the growth inhibition zone.

The diameters of the growth inhibition zones around 0, 0.5, 2, and 5 wt% concentrations of nanosilver particles were not significantly different at 24 and 48 hours and 1 week; however, the difference with the azithromycin disk was significant.

Considering the lack of a significant increase in the diameter of the growth inhibition zones around 0, 0.5, 2, and 5 wt% ZOE containing nanosilver, it appears that addition of nanosilver up to 5 wt% cannot improve the antibacterial properties of ZOE sealer against E. faecalis.

Microorganisms present in the root canal system of primary teeth are mainly responsible for endodontic infections. Enterococcus faecalis is the most important cause of endodontic failure. Application of sealers that decrease the adhesion and colonization of bacteria, as well as susceptibility to bacterial infections can greatly help in this regard. Using these sealers in conjunction with antibacterial agents, such as nanosilver particles may yield higher antibacterial efficacy.