Fig. 3

Combined effect of cinnamon (2.5 mg/ml) and nicotine on S. mutans planktonic growth. Asterisks indicate significant differences (p < 0.05) with cinnamon water extract compared to samples without cinnamon water extract. The # symbol indicates significant differences (p < 0.05) between S. mutans planktonic growth with cinnamon water extract at different nicotine concentrations and the zero-nicotine concentration with cinnamon water extract. The @ symbol indicates significant differences (p < 0.05) between S. mutans planktonic growth without cinnamon water extract at different nicotine concentrations and the zero-nicotine concentration without cinnamon water extract