Exposure of the biofilm to the LED toothbrush
STERILE
After incubation, the supernatant above the biofilm was removed. The biofilm samples were divided into 5 groups based on the LED exposure time, with 2 biofilm plates in each group. The control group did not receive LED exposure. The other four experimental groups were exposed to the LED toothbrush for 15, 30, 60, or 120 s. To avoid the effect of the acoustic pulsations, the LED toothbrush was switched on and held 2 mm above the biofilm (Figs. The biofilm was scraped off and put in 100 µl sterile PBS. The bacteria suspensions were sonicated and serially diluted (10