Fig. 3
Representative images of bacteria colonies grown on BHI agar showing the antibacterial effect of Ag+–Zn2+ combinations against planktonic E. faecalis. A Blank control group (BLK); B–F E. faecalis incubated with different atomic ratio of Ag+ and Zn2+ (1:1; 1:3; 1:6; 1:9; 1:12); G E. faecalis incubated with AgNO3 only (final concentration, 1.6 × 10−2 mg/mL); H E. faecalis incubated with Zn(NO3)2·6H2O only (final concentration, 33.6 × 10−2 mg/mL). I Comparison of bacterial CFU counts among groups. (Asterisk: significant difference when compared with BLK; ▲significant difference when compared with the Zn2+ only group; #significant difference when compared with the Ag+ only group; p < 0.05)