Fig. 3

Assay of the biofilm formation by S. mutans UA159. a Inhibitory effect of TFs on the biofilm formation quantified by crystal violet staining assay. Data obtained from three biological replicates were shown as mean ± standard deviation. “*” represents that there is a significant difference between two studied groups (***p < 0.001). The difference was compared between the group with TFs added and the NC. Representative images showing the inhibitory effect of TFs on the biofilm formation by using confocal laser scanning microscopy (b) and a scanning electron microscope (c). The live and dead cells could be stained by SYTO® 9 and propidium iodide (PI) nucleic acid stains, respectively