Introduction. Introduction. Primary hypothyroidism refers to a common pathological condition associated with thyroid hormone deficiency. Among all thyroid diseases, its share reaches 20%, while the detection rate tends to grow steadily every year in all age groups. An urgent task remains to study the dental status against the background of thyroid diseases developing as a result of iodine deficiency, as well as due to a relative shortage of thyroid hormones. The purpose of the work is to identify the relationship between the quality of the performed restorations and the properties of oral fluid in patients with primary hypothyroidism. Materials and methods. The main study cohort included 60 women with a primary diagnosis of primary hypothyroidism aged 44–59 years. The comparison group consisted of 30 patients without thyroid pathology, identical in sex and age. All patients were evaluated for salivary gland secretory activity, oral fluid properties, and quality of direct oral restorations performed. Results. In the main group of the study, a decrease in the salivation rate, an increase in the viscosity of the oral fluid and a shift in saliva pH to the acidic side relative to the results obtained in the comparison group were detected. Assessment of the quality of direct restorations performed showed an increase in the number of their insolvency in patients of the main group, relative to the comparison group. Discussion. Deficiency of thyroid hormones in primary hypothyroidism is accompanied by a change in the properties of the oral fluid and the quality of direct restorations performed in the oral cavity in the distant period. Conclusion. The identification of the relationship between dental and somatic health parameters will allow the development of a new treatment approach in patients with primary hypothyroidism.