Cestrum nocturnum leaves have approved to prevent the growth of Streptococcus mutans because i t contains flavonoid Flavonoids are phenolic t hal have abilitv to denaturized protein. The purpose of this study to assess that cestrum nocturnum leaves have antibacterial effect on Streptococcus mutans. The melhod of this research i s laboratory experimental with Pos t Test Only Control design. The …