Abstract : Pathology of the hard tissues of the teeth is one of the most important problems of dentistry. The most common types of damage to the hard tissues of the teeth are caries, wedge-shaped defects and pathological erasability [1-3, 6-8]. The damage to the hard tissues of the teeth is often caused by general disorders of mineral metabolism, including pathology of the thyroid and parathyroid glands.The attention of many studies is drawn to the structural features of the hard tissues of the teeth in their pathology. [4—6, 11—21]. However, despite the large number of works devoted to the study of the hard tissues of the tooth in their pathology, in this section of dentistry there is a lot not studied.