Dental plaque is a mouth cavity health problem related to microbial biofilm, where Streptococcus mutans is predominant. Adding of essential oils blend in mouthwash has been reported to increase the dental plaque inhibitory activity. The essential oils of clove leaves (Syzygium aromaticum (L.) Merr. & Perry) and cinnamon cortex (Cinnamomum burmanni Nees ex 81.), are known as potential antibacter…