Comparison Between Antibacterial Effect of Chlorhexidine 0.2% and Different Concentrations of Cyperus rotundus Extract: An In vitro Study

AIMS AND OBJECTIVES: Modern methods of caries prevention concentrated on natural ingredients usage such as probiotics and polyphenols that are safer for young children with Streptococcus mutans inhibitory properties. The purpose of this study was to compare antibacterial effects of different concentration of Cyperus rotundus extract and chlorhexidine (CHX) 0.2% mouthwash on S. mutans and Lactobacillus acidophilus. MATERIALS AND METHODS: In this in vitro study, the antibacterial effectiveness of the C. rotundus extract and CHX was compared with minimum inhibitory concentration (MIC) test in tube, minimum bactericidal concentration (MBC) test in solid medium, and disc diffusion for measurement of inhibition zone. Data were analyzed using one-way ANOVA, one sample t-test, and independent sample t-test statistical methods by SPSS. 24 software (SPSS Inc., Chicago, USA). RESULTS: MIC and MBC values of the C. rotundus extract were obtained 225 and 450 mg/ml, respectively, for S. mutans and 108 and 225 mg/ml for L. acidophilus, which are more than CHX (0.5, 1 res.). The inhibition zone increased in a dose-dependent manner but lower than CHX. CONCLUSION: The C. rotundus extract had antibacterial effects (bactericide and bacteriostatic) on S. mutans and L. acidophillus. Although this effect was lower than CHX. With regard to adverse effect of CHX, this extract can be a potential antibacterial agent.