To study the microstructure of dentin of teeth with hypersensitivity and the impact on them of the proposed interventions in the treatment, the method of scanning electron microscopy was used. We studied 32 samples of permanent teeth with signs of dentine hypersensitivity. All samples were divided into 4 groups. In the first group, fluoride-containing varnish was applied to tooth samples, in the second group, propolis tincture, in the third group, low-level laser therapy was used, in the fourth group, combined action of propolis tincture and low-level laser therapy. For the clinical study, 104 patients with generalized chronic periodontitis with dentine hypersensitivity were selected from the total number of the patients examined. The patients who participated in the study were divided into 4 groups depending on the treatment of dentine hypersensitivity. The clinical examination of patients before and after treatment included the determination of the index of the prevalence and of intensity of dentine hypersensitivity, of the severity of dentine hypersensitivity on the visual analogue scale of pain and on the Schiff scale; and of the excitability of the pulp of sensitive teeth using electroodontometry. In the first group of patients, hypersensitivity of teeth was treated with fluoride-containing varnish, in the second, with propolis tincture, in the third, with low-level laser therapy, in the fourth, with the combined use of propolis tincture and low-level laser therapy. The scientific novelty of the study consists in that for the first time the use of bee product and low-level laser therapy was combined to increase the effectiveness of treatment of dentine hypersensitivity in patients with generalized periodontitis. According to the scanning electron microscopy, information on the diameter of the dentinal tubules in the patients with dentine hypersensitivity was supplemented. At a magnification of 500 times, entrances to the dentinal tubules in the form of pores, the diameter of the visualized pores is (2–5) × 10-6 m are observed on the surface of the dentin. The average number of open dentinal tubules in the dentin of hypersensitive teeth is 144.22±12.68 on an area of 2,5 × 10-9 m2. The information on the formation of double walls and two-layer structure of dentinal tubules after low-level laser therapy has been supplemented. It is established that on using fluoride-containing varnish, as well as tincture of propolis, an acid-resistant film is formed on the surface of the exposed dentin. After daily brushing for one week, a layer of fluoride varnish on the dentin surface was preserved, and after using propolis tincture, it was found that the resulting film was completely removed from the tooth surface. However, in percentage terms, the average number of closed dentinal tubules was 54,25±1,71%, and of open dentinal tubules 45.75±1.71%. For the first time, changes in the microstructure of dentin in the form of dentinal tubule obstruction due to the combined use of bee products and low-level laser therapy in vitro were identified. It was found that, on average, there were namely 93.55±1.11% closed dentinal tubules after treatment of tooth samples with 6% citric acid and 84.82±4.09% after storing the samples in the oral fluid for a week and cleaning them daily with a soft toothbrush. According to the results of the examination, the scientific data on the invariance of the electrical excitability of the pulp before and after treatment of dentine hypersensitivity in patients with generalized periodontitis were expanded by all the used methods. The effectiveness of the combined use of propolis tincture and low-level laser therapy has been proven by comparative clinical evaluation of tooth sensitivity in the long term and shows the advantages of the proposed method. It was proved according to the intragroup analysis that a year later the rate of the index of the prevalence of dentine hypersensitivity was 78.67% less than that obtained before treatment of dentine hypersensitivity (p<0.05), and the rate of the index of intensity of dentine hypersensitivity was lower by 64.29% (p<0.05). The sensitivity index for the visual analogue scale decreased by 78.03% compared to the index obtained before treatment (p<0.05). The average values of sensitivity to cold stimulus on the Schiff scale were lower by 78.93%, and to tactile stimulus were lower by 70.56% compared with the values obtained before treatment (p<0.05). The lowest values of the index of the prevalence of dentine hypersensitivity, the index of intensity of dentine hypersensitivity, the index for the visual analogue scale and Schiff scale were obtained in the group with the combined use of propolis tincture and low-level laser therapy (p<0.05). For the first time, a method for the treatment of dentine hypersensitivity in patients with generalized periodontitis with the combined use of bee product and low-level laser therapy was substantiated and developed.
