Figure 4.

Bacterial numbers in droplets and aerosols that fall around the dental chair. Areas positively detected in the A group (None) were selected, and the effects of the B group (oral suction) and the C group (extraoral and oral suctions) on the bacterial numbers grown on BUI and R2A agar plates are presented. Locations in No. 1–4 and No. 6–8 were indicated in Figure 1. The data indicate the mean ± standard deviation (SD) of three independent experiments. The asterisks indicate a significant difference between two groups (*: p < 0.05, A vs. C, and B vs. C) and (**: p < 0.05, A vs. B, and A vs. C), and among the three groups (***: p < 0.05, A–C).