Comparison of Effects of Thyropathic Drugs on Experimental Dental Caries and Salivary Gland Function

¹ Indiana University Medical Center, Departments of Biochemistry and Oral Pathology Indianapolis, Indiana

Studies were designed to investigate the effect of potassium thiocyanate on experimental dental caries and its effect on the salivary and thyroid glands in comparison with the known effects of propylthiouracil. The results suggested that potassium thiocyanate administered at a high dosage had no adverse effect on dental caries, in comparison with the cariogenic effect observed for propylthiouracil, even though the effect on the structure of the thyroid gland was similar to that induced by propylthiouracil. Furthermore, potassium thiocyanate did not induce an effect on the microscopic structure of the salivary glands similar to that of propylthiouracil. At a lower dosage level, potassium thiocyanate significantly increased dental caries. There was no decreased salivary gland function noted in the animals receiving potassium thiocyanate, although those animals receiving propylthiouracil had a reduction in salivary flow and an increase in salivary viscosity. These collective studies indicate that some mechanism other than the general induction of hypothyroidism by chemical goitrogens is responsible for this alteration in caries incidence and salivary function as found in propylthiouracil-treated animals.