The state of the barrier function of the oral cavity of patients with a history of acute respiratory disease of COVID-19

ABSTRACT. The entrance gate for the SARS-CoV virus is the system of mucous membranes of the upper respiratory tract and oral cavity, which creates the first line of defense of the body against the invasion of foreign agents. Objective to the study is the nature of insemination of the oral mucosa, the density of bacterial population and the adsorption capacity of the buccal epithelium in the post-covid period. Materials and methods. 162 patients who suffered acute respiratory disease of COVID-19 took part in the study, including 54 people. - light form, 69 people. - of medium difficulty and 39 persons. - heavy form. The control group consisted of 30 healthy patients. The clinical and laboratory examination was conducted on the basis of the dental department of the University Hospital of Ternopil during 2020-2022. The results. In patients with a history of a mild form of COVID-19, there is only a quantitative increase in the autochthonous microflora. The colonization index of the buccal epithelium is lower (1.54±0.09) um. units, than in patients of the control group. In patients with a medium-severe form, there are qualitative and quantitative changes in the microflora of the oral cavity, pathogenic and opportunistic microorganisms are often released in large quantities. The colonization index decreases to 1.23±0.01 um. With a severe form of COVID-19, significant changes in the microecology of the mucous membrane are observed - a decrease in the colonization index to 0.57 units. and significant deviations in the character of the microflora, a feature of which was the presence of associations of pathogenic microorganisms. Significant disturbances in the microecology of the mucous membrane of the oral cavity, the development of grade III-IV dysbacteriosis are signs of a significant decrease in the protective barrier properties of the mucous membrane. Conclusions. The intensive growth of pathogenic and conditionally pathogenic non-resident microorganisms is accompanied by the growth of "quorum sensing", which stimulates the manifestation of their pathogenic properties and reduces the barrier function of the mucous membrane of the oral cavity. The obtained results of the assessment of the state of the barrier function of the oral mucosa, the detected violations in the colonization resistance of the oral mucosa of the post-covid syndrome dictate the need to develop and implement in clinical practice an algorithm for the examination of a dental patient with post-covid syndrome.