Antimicrobial effect of propolis on Streptococcus mutans

We choose two types of propolis extracts; watery and ethanolic; to estimate their activity against the most cariogenic microorganism; Streptococcus mutans, and evaluate this activity in vitro compared with chlorohexidine and tetracycline as negative controls, using the turbidity method, Both watery extract of propolis - WEP and ethanolic extract of propolis - EEP - show good inhibitory effect with significant variance compared with chlorohexidine, which also had better effect than tetracycline against Streptococcus mutans. The WEP at (1%) was the best antimicrobial solution in this study.