Figure 1. Representative microscopic images of dogs apical and periapical tissues stained with HE and evaluated under conventional light microscopy (left images) and fluorescence microscopy (right images). A and B: healthy tooth, C and D: tooth with untreated periapical lesions; E and F: periapical lesions endodontically treated in a single session; G and H: periapical lesions endodontically treated in two sessions with EGCG-based paste and I and J: periapical lesions endodontically treated in two sessions with calcium hydroxide-based paste. Magnification 5X.