The increase of the caries resistance of dental solid tissues by injections of iodine-containing thyroid hormones
In experiments with 390 outbred male rats with different thyroid status the fact that crowding- stress (the congested keeping of animals: 40 animals are in a cage during the first 30 days, in the next 30 days there were 30 animals per cage) causes caries of hard tooth tissues and potentiates the cariogenic effect of the high carbohydrate diet of Stephen (used within 60 days) has been established. Hypothyroidism (caused by injections of mercazolilum in the dose 25 mg / kg in the first month and a half of this dose in the second) stimulates manifestation of these effects, while similar to physiological doses of L-thyroxine (28 days 1.5-3.0 mcg / kg and then in the dosemcg / kg till the end of the experiment) limit them. Behind the increase of resistance of dental solid tissues to caries by iodine-containing thyroid hormones is the increase of the structural and functional stability of the enamel, its density, the mineralizing potential, the level of calcium and the antioxidant activity in the saliva.