Figure 2: Morphological characteristics of the molar caries in the rats’ mandibles.
(a–c) Macroscopic appearances of mandibular molars. (a) A partial coronal defect (arrow) of a first molar (M1) in a Lean rat. (b) A partial coronal defect (arrow) of a second molar (M2) in a ZF rat. (c) A complete coronal defect (arrowheads) of a M1 and M2, and a partial coronal defect (arrow) of a third molar (M3) in a ZDF rat. (d–f) A soft X-ray photograph of the mandible. (d) The parts that correspond with the photo in (a); the radiolucent area in the alveolar bone is not observed. (e) The parts that correspond with the photo in (b); the radiolucent area is observed around the dental root of M2 (arrowhead). (f) The parts that correspond with the photo in (c); the radiolucent area expands extensively around the dental root in the periodontal tissues (arrowheads).