Changes in the quantitative indicators of non-specific resistance systems of the body indicate a damage to homeostasis in the body and the development of a pathological process. The state of defense systems largely determines the course and provides a predictive characteristic of the intensity and effectiveness of treatment measures. In patients with inflammatory processes of periapical tissues, there is an imbalance of factors that characterize the state of local resistance of the oral cavity and the mucous membrane of the gums. Also, quantitative and qualitative changes in indicators of phagocytosis, chemotaxis of leukocytes, secretion of cytokines, immunoglobulins, and bactericidal activity of humoral factors of the body's defense were observed. Laboratory animals with experimental model of ulcerative-necrotic gingivitis by chemical burn were divided into three groups: intact, control, and experimental. Animals of the control group were not treated; in the experimental group, complex of drugs was applied to the ulcer surface, which included Thiotriazoline ointment, Zinc oxide, and 0.05% Chlorhexidine solution. In the selected periods of observation (3rd, 5th, 7th, and 10th days), cytological examination of smears was used to determine the adsorption reaction of microorganisms (ARM) by counting the number of bacteria adsorbed on the surface of each epithelial cell (based on 100 cells). At the beginning of the observation, sharp decrease in the number of highly differentiated cells was noted in the smears of animals of the control group, cells of the III stage of differentiation prevailed, and the IDC decreased to 67.52% of the level of intact animals. In all subsequent periods, animals of the control group showed a gradual increase in the IDC index due to an increase in cells in the V stage of differentiation on the surface of the ulcer. The CDI value was significantly different from the norm on the 5th day, with a value of 75.15% of the physiological level, and on the 7th day, with a value of 87.54%. Only on the 10th day was an unreliable difference from the average indicator with 99.13% to its value. In the experimental group, on the 3rd day, sharp and reliable decrease in the number of highly differentiated pools of epitheliocytes and the dominance of cells in the III stage of differentiation was observed, the number of which reached the value of 44.0±1.5%. As a result, at this time, the CDI value decreased relative to the indicator of intact animals to 69.85% of its level. At the end of the observation, the CDI value reliably exceeded the level of intact animals by 4.12%. The most significant decrease in the value of ARM in animals of the control group was detected on the 3rd day, which in percentage value was 76% of the value of intact animals. On the 5th day, the value of "ARM +" increased slightly (only by 4%) to 80% of the physiological norm, and on the 7th day by another 5.5% to 85.5%. Even at the end of the experiment, the "RAM +" indicator in the animals of the control group was significantly lower than that of the intact animals. It was equal to 90% of it. In the experimental group, unlike the control group, satisfactory state of local non-specific resistance in the area of the damaged mucosa was observed only on the 3rd and 5th days. The value of "ARM+" in these terms was only 79.46% and 83.6% of the value of intact animals, respectively. Due to the local effect of the developed complex of drugs, the state of non-specific resistance on the 7th day of observation reached a value corresponding to the "good" level. The "ARM +" percentage value increased to 93.6% of intact animals. At the end of the observation, it reached 97.87% of the physiological norm. Therefore, the cytological study's data coincided with the results of a visual examination of the course of healing of local gingivitis of chemical origin. Due to the additional local anti-inflammatory effect of the developed complex of drugs, it became possible to achieve the normalization of the damaged local non-specific reactivity of the oral mucosa faster (on average, for 3-4 days), and the stimulating regenerative effect promotes more rapid differentiation of epitheliocytes and complete restoration of the damaged area of the gums in a shorter time (on average, 2 -3 days) treatment terms.