Physicochemical indicators of dental patient saliva who have undergone an uncomplicated coronavirus infection

Abstract

Today, it has been proven that saliva is the main medium through which the new COVID-19 coronavirus infection spreads. Since the oral cavity is the gateway for the SARS-CoV-2 virus, the degree of change in the physicochemical parameters of the saliva of people who have had coronavirus infection compared to people who have not had COVID-19 is of interest. This study involved dental patients of the first and second health groups with a history of chronic generalized periodontitis of moderate degree in the stage of remission. We studied physicochemical parameters of saliva such as pH, surface tension and base buffering capacity. The results of this stage of the study showed saliva acidification, that is a decrease in pH in people who had had a new coronavirus infection compared to the indicators of people from the control group. The average values of the surface tension of saliva in patients of the control group are 30% less than in those who have had COVID-19. This indicates that the saliva of people who have not been sick with the new coronavirus contains more surface-active agents (surfactants). Surfactants provide rinsing and disinfecting functions of saliva, therefore, it can be concluded that these functions are less pronounced in patients who have recovered from COVID-19. The base buffering capacity of the saliva of patients who have had COVID-19 is, on average, 35% higher than that of people from the control group. Thus, the pH and the base buffering capacity are in correlation: the lower the pH value, the higher the acidity of the saliva and the higher the base buffering capacity is. At the second stage of the study, similar physicochemical parameters of patients’ saliva were measured after the application of an oral spray containing a synthetic peptide (ZP2) of the active center of granulocyte-macrophage colony-stimulating factor. This spray was used as an antibacterial therapy for the oral cavity after professional hygiene of patients. In 5 minutes after spray irrigation, an increase in saliva pH was observed in all test subjects within the physiological norm. In patients, regardless of their anamnesis, the surface tension of saliva changed in different ways. In a number of people, it increased, which indicates an increase in the concentration of surfactants in saliva, while in others it decreased, which can be explained by the high rate of penetration of surfactants from saliva through the gums into the blood. After the application of the ZP-2 peptide, the base buffering capacity of saliva decreases or remains unchanged. In patients of the control group, the indicators of the base buffering capacity of saliva change less than in patients who have undergone COVID-19. All the studied physicochemical parameters of saliva in patients who had had uncomplicated COVID-19, three months after receiving two negative results for the SARS-CoV-2 virus, remained within the physiological norm.