The Comparison of Antimicrobial Effect of Nigella sativa Nanoparticle and Chlorhexidine Emulsion on the Most Common Dental Cariogenicic Bacteria

Background: Tooth decay and periodontal disease are the most common chronic human and oral diseases, respectively, and bacterial plaque has a major role in their occurrence. Because of the importance of plaque control, this study was done to compare the antimicrobial effects of Nigella sativa nanoparticles and chlorhexidine emulsion on the most common dental cariogenicic bacteria. Methods: In this experimental study, the effects of 0.2% chlorhexidine mouthwash and Nigella sativa nanoparticle with different dilutions on Streptococcus mutans, Streptococcus sobrinus, Streptococcus salivarius, Lactobacillus acidophilus, Minococcal fecalis, and Enterococcus fecalis were compared using minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assessment. Data were analyzed by SPSS Version 16.0 software, and statistical tests, including an independent sample t test. Results: Mean diameters of growth inhibition zone because of the nanoemulsion of Nigella sativa nanoparticle was close to each other in different bacteria (p=0.665). In addition, there was no significant difference between these values because of different dilutions of nanoemulsion even in different microbial species (p=0.778). The MIC and lethal concentrations of Nigella sativa nanoemulsion were similar for Enterococcus faecalis and Streptococcus mutans, and it was higher than other bacteria. In comparison, the MIC and MBC values of all bacteria in chlorhexidine were lower than those of the nanoemulsion. Conclusion: MIC and MBC values showed that Nigella sativa nanoemulsion affects tooth cariogenicic bacteria. Enterococcus faecalis and Lactobacillus acidophilus were the most resistant and susceptible bacteria to this nanoparticle, respectively, while the antimicrobial effects of Nigella sativa nanoemulsion were weaker than the chlorhexidine mouthwash.