Evaluation of Antibacterial and Anti-biofilm Activity of Herbal, with and without Fluoride Mouthwashes on Streptococcus mutans and Streptococcus sanguinis: An In Vitro Study

Mouthwashes play an important role in oral hygiene and prevention of tooth decay by reducing the proliferation of oral microbial flora. The purpose of this study was to investigate the antibacterial and anti-biofilm activity of Persica herbal mouthwash, Mouthwashes with fluoride (Misswake), without fluoride (Irsha) and chlorhexidine 0.2% against Streptococcus mutans and Streptococcus sanguinis, in vitro.

To evaluate the antibacterial effect of mouthwashes on two standard strains of S. mutans and S. sanguinis, were used well diffusion and microbroth dilution methods and to examine their anti-biofilm effects, the microtiter plate method was used. The results were analyzed using SPSS software, version 21 and t-test.

In the well diffusion method, Misswake and 0.2% chlorhexidine mouthwashes had an inhibition zone at concentrations of 500 mg/ml and 500 mg/ml to 125 mg/ml, respectively. The MIC of Persica and Misswake mouthwashes were determined at concentration of 500 mg/ml and chlorhexidine 0.2% at concentration of 31.25 mg/ml. Irsha mouthwash did not have any antibacterial effect. In microtiter plate method, anti-biofilm activity was observed only for 0.2% chlorhexidine mouthwash at concentrations of 125 mg/ml to 31.25 mg/ml. Persica, Misswake and Irsha mouthwashes did not have any anti-biofilm effects on the studied bacteria. The results showed that 0.2% chlorhexidine had a significant antimicrobial and anti-biofilm effects on the studied bacteria compared to other mouthwashes (P<0.05).

0.2% chlorhexidine mouthwash has a very high antimicrobial power than other mouthwashes, but our study suggests that Persica and Misswake mouthwashes can be used as a mouthwash with proper antiseptic properties.