Fig. 2

Bactericidal effect of 310 nm UVB-LED irradiation on oral bacteria. Each bacterial suspension (0.1 ml) in 96-well plates was irradiated by a UV-LED. The suspensions were serially diluted and incubated on agar plates at 37 °C anaerobically. Colonies on the plates were counted after incubation for 1–7 days. Bactericidal levels are indicated as viability (%). (n = 3 or 5, means ± SE; **P < 0.01 vs. 0 s, *P < 0.05 vs. 0 s)