Comparing the Effect of Herbal Mouthwash Containing Hydroalcoholic Extracts of Cyperus rotundus L. and Thymus vulgaris L. and Chlorhexidine Mouthwash on Common Periodontal Pathogens

Gingivitis is an inflammatory disease of the gums caused by accumulation of dental plaque. It can become a chronic periodontal disease if plaque spread below the gum line. The most common pathogens that contribute to periodontal disease include Streptococcus mutans, Streptococcus pyogenes, and Candida albicans. Due to the side effects of common treatment by chlorhexidine mouthwash, novel treatments to fight such microbes are much of interest. This study aimed at comparing the antimicrobial effect of herbal mouthwash containing the extracts of nut-grass and thyme and chlorhexidine mouthwash on common periodontal pathogens.

First, Cyperus rotundus and Thymus vulgaris were collected, powdered, and the hydro alcoholic extract of the mixture of two plants and the methanol extract of each plant were taken. Then, a mouthwash containing combined extract of the two plants was prepared using different exipients. To evaluate the antimicrobial effect of the extracts, S. mutans, S. pyogenes, and C. albicans were used. After determining the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), the effect of mouthwash on S. mutans biofilm formation and degradation was investigated.

The MIC of the mouthwash formulation against S. mutans, S. pyogenes, and C. albicans were 0.625, 0.039, and 2.5 mg/ml, respectively. The MBC of the mouthwash for each microorganism was 1.25, 0.078, and 10 mg/ml, respectively. The herbal mouthwash significantly inhibited biofilm formation compared to the positive control (P<0.05) which showed no significant difference compared to the negative control (P>0.05). Findings showed no significant difference in biofilm destruction between the herbal mouthwash and the positive control (P>0.05).

The prepared herbal mouthwash showed significant antimicrobial and anti-biofilm effects, and was much more effective in preventing biofilm formation than the standard treatment by chlorhexidine.