Fig. 4

Changes in number of planktonic cells and preformed biofilms following incubation of EGCG with/without LL-37. Representative images of bacterial cells observed by field emission-scanning electron microscope (working distance: 10 mm, field width: 5 μm) are shown. Streptococcus mutans suspensions incubated in the presence (a) or absence (b) of 0.2 mg/mL EGCG for 24 h. Streptococcus mutans biofilms on MBEC pegs incubated with 0.2 mg/mL EGCG (c), 0.2 mg/mL EGCG, and 80 μg/mL LL-37 (d), or BHI medium (e) for 24 h. The white arrow indicates the “ring” phenomena around damaged cells