Alloxan-induced Hyperglycemia Causes Rapid-onset and Progressive Dental Caries and Periodontitis in F344 Rats

We have previously shown that diabetes increases dental caries, and periodontitis might be a secondary change resulting from dental caries in spontaneous diabetic rodent models. However, the lesions in these models were slow to manifest, and the intensity and frequency were mild and varied among individuals. The goal of this study was to confirm the reproducibility of caries development in chemically induced diabetic rats and investigate whether alloxan, which induces immediate and severe hyperglycemia in experimental animals, increases the lesions. Female F344 rats were examined 13 and 26 weeks after dosing of alloxan. Alloxan injection induced severe hyperglycemia in two-thirds of the rats. Progressive molar caries and periodontitis were already induced in all diabetic rats 13 weeks after dosing of alloxan, although the lesions were not observed in nondiabetic rats. Histopathologically, dental caries initially developed in the crown, then spread into the dental root, entered the periodontal connective tissue via the apical foramen, and progressed to periodontitis. In conclusion, alloxan-induced severe hyperglycemia is capable of causing rapid-onset and progressive dental caries and periodontitis in rats.