Figure 4.

(A–G) Scanning electron micrographs of coronal dentine after selective carious tissue removal and treated with dentine conditioner (polyacrylic acid) (original magnification X6000). (A) Cavity floor dentine with the smear plugs existed in the orifice of dentinal tubules and a small amount of cocci (red arrow) attached to the walls of the tubules; (B) upper portions of occlusal half of coronal dentine and no bacteria colonization; (C, D) middle and lower portions of occlusal half of coronal dentine consisting of a small amount of cocci and filamentous (green arrow) bacteria; (E, F) upper and middle portions of pulpal half of coronal dentine with a small amount of bacilli (blue arrow); (G) lower portions of pulpal half of coronal dentine and no bacterial invasion into the tubules.