Electronic microscopic research on periodont in experimental two-weight opioid action and after its over for four weeks

Abstract

Due to the harmful effects of opioid agents in the uncontrolled use of them, it is impossible to ease the early manifestations of damage to the tissues and organs of the oral cavity, which is a pressing problem of today. The purpose of this work was to investigate the features of the sub-microscopic organization of the structural components of the periodontium under the action of an opioid analgesic for two weeks and its four-week withdrawal in the experiment. The study was conducted on 22 adult rats-males of the Wistar line, weighing 160 g, 4.5-6 months of age. Animals were administered intramuscularly daily, once a single opioid analgesic nalbuphine for the first two weeks, in terms of the mean therapeutic dose for the rat, as well as for the mean weight of the test group (0.212 mg/kg), and subsequent four weeks. The fragments of soft periodontal tissue were used for electron microscopic examination. Submicroscopically expressed destructive changes in periodontal tissues were not observed. However, the positive dynamics of regeneration of periodontal components at the ultrastructural level were also not revealed. In the cytoplasm of cells of the epithelium of the free part of the gums, there is destruction of organelles, partially damaged mitochondrial cristae, poorly contoured tonofilaments, shallow karyolemma invaginations, thickened areas and damaged desmosomal contacts. In the surface areas of the periodontium, the collagen fibers are partially stratified, there is moderate swelling of the intercellular substance of the connective tissue, part of the fibrocytes invaginating the karyolemma of the nucleus and placement of heterochromatin in the periphery. Ultrastructurally in the cytoplasm of the macrophage, lysosomes are detected, phagosomes are scarce, indicating a slight damage to the structures. In the gaps of the blood capillaries, blood cells are formed, mainly erythrocytes, in the perinuclear part of the cytoplasm of organelles are few, mitochondria with electron-light matrix and small cristae, perivascular edema is insignificant, there are destructively altered mitochondria in the cytoplasm of endothelial cells of venules, the basement membrane is thickened, the perivascular spaces are enlarged. Thus, at the end of the sixth week of the experiment, no short-term irreversible changes in the ultrastructural organization of the periodontal components were detected in the short-term effect of the opioid for two weeks and its subsequent four-week cancellation. However, the complete restoration of the structural components of the periodontium is not observed, there are signs of reactive changes, reparative processes are slowed.