Figure 4: Histopathologic features of molar caries and alveolar bone resorption. AB: alveolar bone; C: dental caries; D: dentin; G: gingiva; P: dental pulp. (a and d) A Lean rat’s mandible corresponding to that of the M1 molar area in Figure 2a and 2d. (b and e) A ZF rat’s mandible corresponding to that of the M2 molar area in Figure 2b and 2e. Inflamed periodontal connective tissue (*) is observed. Note the abscess in the apical part of the tooth (arrow) adjacent to the pulpal inflammation. (c and f) A ZDF rat’s mandible corresponding to that of the M1 molar area in Figure 2c and 2f. Granulation tissue (*) contains inflammatory cells and epithelial cord with a downward elongation from the gingival surface along the dental root. Note the abscess in the apical part of the tooth (arrow) adjacent to the pulpal inflammation. Bar, 500 µm.