Fig. 5

Confocal laser scanning microscopy images of remaining biofilms on orthodontic brackets after each biofilm removal treatment. Dual-staining method using SYTO-9 and propidium iodide was used to evaluate the viability of remaining Streptococcus mutans after each decontamination treatment. SYTO-9 stained all bacterial cells, while propidium iodide stained dead bacterial cells. The white scale bar represents 500 µm