Background and Aim: Streptococcus mutans (S. mutans) is the main etiological bacteria present in the oral cavity that leads to dental caries. Different preceding studies have recognized green tea to have anti-inflammatory, antiviral, antifungal, antioxidant, protein-denaturing, anti-mutagenic, anti-diabetic, anticarcinogenic, and antibacterial characteristics. The aim of our study is to investigate the effects of rinsing with 2% green tea solution for 5 min. on S.mutans count in both saliva and plaque and Gingival Bleeding Index (GBI). Method: Study was carried out in university hospital of Riyadh Elm University (REU) on 105 subjects. Each subject underwent two phases before and after rinsing with 2% green tea solution for 5 min. In each phase we measured GBI and S.mutans count in saliva and plaque. Result: The result of this study showed statistical significant differences between pre- and post- rinsing with green tea concerning S.mutans count in saliva and plaque and GBI. Conclusion: S.mutans count in both saliva and plaque is reduced after rinsing with 2% green tea solution for 5 min. and there is a marked reduction of GBI score.
