Effects of continuous glucocorticoid infusion on the progression of dentinal caries in growing rats

Abstract

This study was undertaken to test the effects of a low dose of continuous glucocorticoid infusion on the rate of progression of dentinal caries in molars of young rats. Forty-seven rats were inoculated in the mouth with Streptococcus sobrinus and fed ad libitum a cariogenic diet and 10% sweetened water. After 10 days of caries initiation ten animals were killed to serve as a reference group. In the rest of the animals the cortisone or placebo pellet was implanted subcutaneously in the back of the neck. The daily release of cortisone was 0.42 mg per rat. Sweetened water was changed to pure water, and the diet was the same cariogenic diet. After 6 weeks of medication the areas of dentinal caries were quantified planimetrically. Schiff's staining was used to classify caries. Although cortisone medication slightly increased the number of carious lesions, statistical significance was not reached. However, compared with the placebo group, the rats receiving cortisone medication showed significantly increased dentinal caries progression and severity of lesions. This study suggests that glucocorticoids with a cariogenic diet reduce the intrinsic modulation or response of the odontoblasts to caries attack.