Antimicrobial Effect of Nano Zinc Oxide Against Oral Microrganism at Different Sizes
The purpose of this study was to evaluate the antimicrobial effect of various sizes and concentrations of zinc oxide nano particles on some microorganisms in the oral cavity, including Streptococcus mutans (SM) , Enterococcus faecalis (EF), Lactobacillus fermentum(LF) and Candida albicans(CA)
Methods and Materials:
Solutions of Nano-zinc oxide powder were prepared at a concentration of 10µg ml-1 with sizes of 20,40and 140 nm.
The antimicrobial effects were determined using the well diffusion and disk diffusion methods.
And the zone of inhibition was measured by a ruler (in mm).
(IZ) data were analyzed by ANOVA and Bonferroni test.
Minimum inhibitory Concentrations (MIC) and minimal bactericidal concentrations (MBC) of ZnO nanoparticles were determined by the broth micro- dilution method in Mueller-Hinton medium (for SM and EF), MRS and sabouraud dextrose.
The most of IZ were observed in sizes of 20,40nm for SM. And in size of 140 nm were observed for the two bacteria SM and EF, and The lowest IZ in three sizes, is for CA. MIC For CA in sizes of 40 and 140 nm, Was larger than10µ g ml-1 as well as for LF in size of 140 nm. A significant relationship was found between antibacterial activity and particle size against SM (p=0.00), LF and EF (p<0.02).
The antimicrobial activity of zinc oxide nanoparticles increases with decreasing size.The most antimicrobial effect was observed on SM and EF. And SM is more sensitive to changes in particle size, than others.
Key words: Zinc oxide Nanoparticles, antimicrobial effect, size