STRUCTURE AND MINERAL COMPOSITION CHANGES OF DENTOALVEOLAR COMPLEX IN RATS WITH COMBINED ENDOCRINOPATHY

Under the conditions of combined endocrine pathology, systemic metabolic disorders occur, which are the main mechanism of structural and functional changes of organs of oral cavity. It is known, that diabetes mellitus is a trigger for microcirculatory changes in the dental pulp and the decrease in bone mineralizing ability. At the same time, thyroid hormones regulate hydrocarbon metabolism, stimulate glucose uptake, glycolysis and gluconeogenesis. Therefore, the purpose of the study was to investigate the changes of structure and mineral composition of the dentoalveolar complex in rats with iodine deficiency, insulin resistance, and in case of their combination. The examination was carried on 90 female rats, which were divided into three research groups: rats with iodine deficiency, insulin resistance and under the conditions of their combination. For the analysis of mineral status the determination of calcium, magnesium, zinc, manganese and copper content in the erythrocyte mass, teeth and alveolar processes was performed. In addition, the activity of acid and base phosphatases in blood serum of rats was found. Biochemical researches were followed by morphometric analysis of alveolar processes and teeth structure. Morphometric analysis of bones and teeth was performed taking into account the thickness of the bone beams; the area of the intertubercular connective tissue of bone, which accounts on one cell; the optical density of the osteogenic bone matrix; the area of loose connective tissue of the tooth pulp, which accounts on one cell; the optical density of the main substance of loose connective tissue of the tooth pulp. Statistical processing of research results were analyzed by using the mathematical software package Statistic Soft 7.0 using the Student's t-test. Statistically significant difference was considered at p<0.05. It was found that the development of iodine de-ficiency was the reason for the reduction of calcium and magnesium content in the teeth and alveolar processes of examined rats. Impairment of glucose utilization was also manifested by the predominant development of demineralization processes in examined tissues (reduction of calcium and magnesium levels in the examined tissues against the background of increasing the zinc level in the teeth tissues). It is important to note, that combined endocrine pathology was accompanied by more pronounced changes in biochemical parameters, which were confirmed by the data of morphometric analysis. Metabolic disorders were consistent with the results of histological examination, which showed the manifestation of reactive inflammatory changes in the teeth pulp. Thus, in the connective tissue of the pulp a significant number of macrophages, lymphocytes, fibroblasts, fibrocytes was verified. The structural changes also were found in the alveolar processes. In particular, in rats with combined endocrine pathology the bone thickness of the alveolar processes and bone matrix thickness were lower than the analogical indexes in animals with iodine deficiency or insulin resistance. Thus, the development of combined endocrine pathology activates the processes of demineralization of dentoalveolar complex, progression of degenerative-dystrophic changes of bone tissue, enamel and dentin. Violations in mineral homeostasis may indicate pathological changes in structures of periodontium, which makes it possible to detect disorders of solid tissue mineralization in the early stages of endocrine pathology.