Morphological features of enamel in fluorosis of different degrees of severity

Abstract

The occurrence of dental fluorosis is facilitated by a violation of enamel mineralization caused by fluorides, which enter the human body in excess during its development and formation and have a toxic effect on enamel blasts. However, the molecular mechanisms involved in the pathogenesis of fluorosis are not fully understood. Enamel formation is a complex process involving cell proliferation and differentiation through epithelial-mesenchymal sequential secretion of matrix proteins, tissue-specific transport of ions including calcium and fluoride, and precipitation and alignment of enamel crystals through interactions between organic and inorganic molecules. Understanding the morphological features of enamel changes during fluoride intoxication of the human body in the endemic region allows us to clearly understand the need for a comprehensive solution to this medical and social problem. The aim was to study the morphological features of enamel in fluorosis in residents of the endemic region of Ukraine, in particular the Poltava region. The work examines different groups of teeth (both intact and affected by fluorosis) removed for orthodontic or clinical indications in men and women aged 17 to 40 years. Morphological signs were studied first on native, and later on histochemically stained sections. It was established that the violation of the structure of the enamel layer of the teeth in mild and severe fluorosis is characterized by both partial and complete violation of the movement of the enamel prisms with signs of destruction. Fragmentation and homogeneity throughout the entire thickness were found in some areas of the enamel. When evaluating histochemically stained sections of teeth affected by fluorosis, it was established that dystrophic changes in the enamel structure and accumulation of acidic glycosaminoglycans in the lesions are more characteristic of mild and moderate forms. Under the conditions of a severe form of fluorosis, complete destruction of the prisms, fragmentation of the lamella, homogenization of areas on the entire enamel layer, which is due to the uneven distribution of acidic mucopolysaccharides, have been established. Morphologically and histochemically dystrophic changes in the areas of the affected enamel are confirmed by uneven distribution and accumulation of acidic glycosaminoglycans. An assessment of the effect of fluoride intoxication on the state of tooth enamel was carried out, which will allow to expand the possibilities of preventive measures for related specialists, as well as to create and develop additional treatment methods that will contribute to the improvement of physical and aesthetic indicators of teeth. dental health.