ETIOLOGY, CLASSIFICATION
Non-carious lesions are quite common. The prevalence of this condition varies in different countries. According to a literature review, the average prevalence of non-carious lesions ranged from 10% to 23% among individuals not engaged in hazardous industry, in different regions of our country until 1987. Excessive attrition of teeth was 9.2-18%, teeth erosion - 0.9-2.6%, wedge-shaped defect - 2.6-5%, hypoplasia - 1.9-4%. The prevalence of dental fluorosis, associated with high levels of fluoride in drinking water, ranged from 30% to 90% in different endemic areas.
Over recent years, the number of non-carious lesions has been increasing primarily due to the diseases group II (those occurring after teeth eruption) in the European part of Russia. This fact is linked to environmental deterioration in general and the Chernobyl tragedy.
According to U.A. Fedorov and V.A. Drozhina (1997), an increase in the number of non-carious lesions is associated with such factors as drug addic-tionand prolonged or uncontrolled drug administration (salicylates, tetracy-cline, hormones, ergocalciferol and others). As a result, a new clinical entity was added: "Drug-induced and toxic odontogenetic disorders of hard dental tissues occurring before and after teeth eruption". The authors mentioned new forms of necrosis of hard dental tissues - computer-related, toxic (as a manifestation of drug addiction) and a combination of several types of non-carious lesions.
That is why the problem of non-carious dental tissue problems is important nowadays.
Professor V.K. Patrikeev (1968) proposed to divide teeth with non-carious lesions into 2 groups.
1. Teeth with hard tissue disease that occurs during their development: