The dissertation is devoted to the improvement of diagnostics and combined treatment of periodontal diseases in patients with primary hypothyroidism. The prevalence and peculiarities of the occurrence of periodontal diseases in persons with primary hypothyroidism were studied. In conditions of clinical observation, it was found that in patients with primary hypothyroidism the prevalence of periodontal diseases (93,26±2,67%) is manifested by the development of inflammatory and inflammatory and dystrophic lesions of its tissues. The use of only basic therapy drugs is inadequate and ineffective. The scheme of combined treatment of periodontal diseases in patients with the background of primary hypothyroidism, consisting in adding a local action drug to the traditional basic pharmacotherapy, is an antiseptic, a holisal gel (2 times a day, a gel to be used as a gum application for 14 days) and an oral preparation from immunomodulating the action - immunosuppressants (1 tablet 4 times a day for 14 days). The combined use of holissal gel and immune positive affects the clinical signs of periodontal disease and oral hygiene in patients with primary hypothyroidism, changes the contamination of periodontal pockets with clinically significant microorganisms, which provides a return to normocenosis, improves the state of biochemical parameters of bone remodeling, indices of local immune defense, cellular and the humoral link of systemic immunity. Scientific data on bone metabolism in patients with periodontal diseases on the background of primary hypothyroidism has been supplemented. For the first time, it was revealed that in the microbiocenoses of the gingival and periodontal pockets of patients with periodontal diseases in the background of primary hypothyroidism dominated by representatives of anaerobic and extra-anaerobic microorganisms, namely, α-hemolytic streptococci was sown in 93,3% of patients, and 55% in the culture of lactobacilli. In the majority of patients (83.3%) there were strains of porphyromonad, coagulase-positive and coagulase-negative staphylococci (75.0% and 78.3% respectively). An in-depth understanding of the state of general immune defense in patients with primary hypothyroidism combined with periodontal diseases is deepened. The disturbance of cellular and humoral links was determined, which is important in the pathogenesis of the development of periodontal diseases in the background of primary hypothyroidism. The combined use of holissal gel and immune positive affects the cellular and humoral levels of systemic and local immune protection, which is confirmed by the normalization of CD3, CD4, CD8, CD16 as well as lower levels of immunoglobulins of classes A, G, M. This is accompanied by an increase lysozyme activity and decreased sIgA content in the oral liquid.The practical value of the results. Based on clinical observations, results of assessing the state of microbiocenosis of the gums and periodontal pockets, bone metabolism, systemic and local immunity in patients with periodontal diseases in the background of primary hypothyroidism, the treatment and prophylactic scheme, which includes the combined application of the antiseptic of the holissal gel and the immunomodulatory complex, was developed and implemented, was developed and implemented.The use of the proposed combination systemic and local pharmacotherapy has an advantage over standard drug therapy. This is confirmed by a multidirectional pathogenetic effect, the absence of side effects, especially in patients with the background of primary hypothyroidism.