The article presents the results of study effect of quercetin on the indicators of endogenous intoxication syndrome under conditions of experimental periodontitis. One of the key links in the pathogenesis of any inflammatory disease, including maxillofacial area, is endogenous intoxication, an important pathophysiological mechanism of which is the activation of lipid peroxidation. The experimental animals were treated by intramuscular injections with water-soluble quercetin for 7 days. For further research the blood serum was selected in which was determined the content of middle molecular weight molecules and erythrocyte intoxication index. Excessive lipoperoxidation was accompanied by accumulation of peroxidation products and depletion of antioxidant reserves, which led to accumulation of toxic substances. That is why the study of the level of middle molecular weight molecules and erythrocyte intoxication index in simulated bacterial-immune periodontitis is a reliable criterion. Quercetin was able to reduce the expression of endogenous intoxication syndrome in experimental bacterial-immune periodontitis.

In the article was studied the effects of flavonol quercetin on indices of adaptive immune response in experimental animals on the 14th day of the experimental bacterial-immune periodontitis development. Indices of immune protection were determined by the relative number of lymphocytes with CD3+, CD4+, CD8+, CD19+, CD16+ and immunoregulatory index (CD4+ / CD8+) in intact animals and on the 14th day of inflammatory process development in periodontal tissues as well as the therapeutic effects of flavonol quercetin. As a result of the study, characterized changes associated with the activity of both the cell-mediated and humoral-immune response were found, both in the development of experimental periodontitis, and apply of flavonol. In particular, there was an increase in the animal’s blood relative amount of CD8+, CD16+ cells on the 14th day, and content of CD3+, CD4+, CD19+ was decreased. In this case, the immunoregulatory index (CD4+ / CD8+) as an important index of immunological activity was decreased. The apply of flavonol quercetin in the period development of bacterial-immune periodontitis animals functional activity of the T-cell line of the immune system was increased, as evidenced percentage increase of B- and T-cells due to T-helper cells decrease as well as T-killers content during this period of inflammatory reaction in the periodontal complex, in comparison with animals, which were not treated.

The article presents the results of study the changes of ultrastructural organization in the periodontal complex under conditions of experimental bacterial-immune periodontitis development and treatment effect of flavonol quercetin. Experimental bacterial-immune periodontitis in experimental animals was caused by injection of complex mixture of microorganisms diluted with egg protein into periodontal tissue. The evaluation of the ultrastructural character changes in the gingival area of the periodontal complex was carried out on the basis of electron microscopic examination. In a result study on the 7th day of the experiment were observed changes that manifested disorders of the connective tissue and vessels structure. It were also marked increased diffusive leukocytic infiltration of the connective tissue of the mucosal gingival lamina propria. There was some improvement in respect of the electron microscopic structure of the microcirculatory vessels on the 14th and 30th days of the experiment. The performed studies of hemocapillaries submicroscopic organization of the animal’s gums mucous membrane in conditions of application quercetin for experimental periodontitis has shown that flavonol improved structural organization considerably. The use of quercetin improves the organization of all ultrastructured components of the periodontal complex in experimental periodontitis.

Introduction. Odontopreparation is an integral step in orthopedic dental treatment with non-removable orthopedic constructions. Correctly performed this stage in the treatment of artificial crowns is a guarantee of the quality of orthopedic treatment. Ensuring a stable geometry of the stump, a ledge of sufficient width on the abutment and the absence of defects on its surface, the clarity of the preparation margin and the correct ratio with marginal periodontal tissues are the most significant criteria for the quality of the intervention. In addition, the quality of the odontopreparation of the orthopedic profile is influenced by the clarity of adherence to the selected algorithm of preparation and the properties of the rotary tool used. The available literature data indicate numerous deviations in the practice of dentistry from the recommended methodology of odontopreparation, which can be explained by the relatively high frequency of complications of treatment with non-removable orthopedic structures. The purpose of the article is to analyze the key factors affecting the quality of fixation and the durability of the functioning of artificial crowns, based on an assessment of the basic principles of odontopreparation for this type of orthopedic structures and the reaction of periodontal tissues based on an analytical review of the literature. Materials and methods. The article presents the data of the literature review on the main factors that are of great importance as the fixation and durability of the functioning of artificial crowns on the stumps of dissected teeth while observing step-by-step odontopreparation algorithms with provision of proper functional and desired aesthetic requirements without negative influence on the condition of the tissue. Conclusion. Based on the analysis of literary sources, it was concluded that the key factors affecting the quality of the formation of the tooth stump to be prosthetized, subject to step-by-step odontoperational algorithms with the creation of conditions for high-quality fixation and durability of the functioning of the artificial crown, ensuring the proper functional and desired aesthetic requirements without negative impact periodontal tissues can significantly reduce the manifestation of unwanted complications, and as a result to increase the effectiveness of prosthetics with artificial crowns.

Inflammatory diseases of periodontal tissues remain one of the most complex and unresolved problems of modern dentistry. The most important internal stimulus for triggering apoptosis is DNA damage in response to various factors (including reactive oxygen species). Mitochondrial transmembrane potential (Δψm) is generated by the electrochemical gradient of protons on both sides of the membrane and is closely related to the functioning of mitochondria, its support is provided by the processes of electron transfer in the respiratory chain. The purpose of our study was to elucidate the pathogenetic role of changes in mitochondrial transmebranic potential in the dynamics of the inflammatory response in experimental bacterial-immune periodontitis and the effects of quercetin (Korvityn) on it. Material and methods. The study was performed on white clinically healthy rats. Experimental bacterial-immune periodontitis in experimental animals was induced by injection of a mixture of microorganisms diluted with egg protein into the tissues of the periodontal complex. Quercetin was administered by intramuscular injection for correction. Evaluation of changes in mitochondrial transmembrane potential of leukocytes was performed by flow cytofluorimetry. Results and discussion. In experimental bacterial-immune periodontitis, the percentage of cells with reduced mitochondrial transmembrane potential among blood monocytes significantly increased. In animals on the 7th day of the study, the number of cells with reduced mitochondrial transmembrane potential among blood monocytes increased significantly compared with the control group. For the next study period (14th day), the number of cells with reduced ∆ψm decreased compared to the 7th day of the experiment. Having analyzed the data of mitochondrial transmembrane potential of blood monocytes on the 30th day of the experiment, we noted that they decreased relative to those obtained on the 14th day of the study, indicating profound oxidative imbalance in cells and destabilization of the mitochondrial membrane. The use of quercetin led to a decrease in the values compared to the data of animals with our simulated pathology on the 14th day, the experiment without the introduction of flavonol, but they remained significantly higher than the control group of animals. Conclusion. Flavonol (Korvityn) quercetin reduced mitochondrial transmembrane potential in experimental bacterial-immune periodontitis, which was evidence by stabilization and attenuation of the inflammatory process