Antibacterial activity of capsaicin on Streptococcus sanguis and biofilms: A, the trend of pH values of Lactobacillus effected by capsaicin in 12h. B, OD values of biofilm of Streptococcus sanguis affected by capsaicin. The capsaicin group consisted of 1/2 MIC experimental capsaicin solution (95% BHI+5% alcohol) and Streptococcus sanguis 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).