Antibacterial activity of capsaicin on Actinomyces viscosus and biofilms: A, the trend of pH values of Actinomyces viscosus effected by capsaicin in 12h. B, OD values of biofilm of Actinomyces viscosus affected by capsaicin. The capsaicin group consisted of 1/2 MIC experimental capsaicin solution (95% BHI+5% alcohol) and Actinomyces viscosus microbial inoculums. The control group consisted of the solution (95% BHI+5% alcohol) and microbial inoculums without capsaicin. The blank group consisted of 1/2 MIC experimental capsaicin solution (95% BHI+5% alcohol) without microbial inoculums. The data are presented as the mean ± SD (n>3). The symbol * means statistic difference between the two groups (p<0.05).