The Effect of Food Hardness on the Development of Dental Caries in Alloxan-Induced Diabetic Rats

Figure 3

Morphological characteristics of molar caries in the mandibles of female F344 rats. M1: the first molar, M2: the second molar, and M3: the third molar. (a–c) Macroscopic appearance of molar caries. (a) Normal molars. (b) Partial coronal defect (arrow) of M1 and complete coronal defects (asterisks) of M2 and M3. (c) Complete coronal defects (asterisks) of all of the molars (M1–M3). Scale bar = 2 mm. (d–f) Soft X-ray images of the molar caries. (d) Normal molars. (e) Corresponding to the macroscopic observation, dental caries with a focal (arrow) or an extensive radiolucent area (asterisks) in the dental crown is observed. The caries were graded as 2 (M1), 4 (M2), and 3 (M3). (f) The dental crowns are completely absent in all of the molars (grade 4, asterisks). Scale bar = 2 mm. (g–i) Histopathological features of the carious lesions. (g) Normal molars. (h) Moderate-to-severe carious lesions. Dentin caries spread over a large part of the dental crown. (i) Severe carious lesions. Dentin caries expands to the dental root, resulting in a completely decayed crown. HE stain. Scale bar = 500 μm.