Effect of antimicrobial activity of Teucrium polium on oral Streptococcus mutans: a randomized cross-over clinical trial study

Abstract Background : The purpose of this study was to determine the effect of a mouthwash containing Teucrium polium herb on Streptococcus mutans in mouth. Methods : This study was a randomized, crossover, double-blind clinical trial, where twenty-two volunteer dental students were randomly divided into two groups. The study had two phases. In each phase, one group was chosen as the intervention group, while the other one was the control group. Both the intervention and control groups were given the mouthwash with and without Teucrium polium , respectively. S. mutans of saliva were measured before and after each phase to compare the effects of the mouthwashes. A three-week washout period was considered between the two phases. An independent two-sample t-test was used to compare the mean number of S. mutans colonies. Additionally, a standard AB/BA crossover model was used to find the results of the treatment and the carryover effect on the residual biological effects. The significance level was considered 0.05 in this experiment. Results : There was no significant difference between the two groups in the number of S. mutans before using the mouthwashes. Using the mouthwash containing Teucrium polium extract significantly decreased the number of S. mutans colonies in both phases (P = 0.002). Conclusion : The results of this study showed that the mouthwash containing aqueous extract of Teucrium polium can significantly reduce the colonization of S. mutans in human saliva. Trial registration : Ethical issues approved by the Ethics Committee of the Rafsanjan University of Medical Sciences with the approval number of 937/9/31 and IRCT code No. IRCT2013121815842N1, approved in 06.16.2014. The study was done in September till November 2014.