Study of the morphological structure of enamel and correlation of its chemical composition with dentin in intact teeth and with a cervical pathology

Introduction
The increase in the intensity of caries and non-carious lesions of the teeth leads to significant disorders in the dentoalveolar apparatus manifested themselves not only as aesthetic but also as functional disorders in the absence of timely adequate treatment. Objectives: The increase in the prevalence and intensity of cervical lesions of hard dental tissues is the cause of aesthetic and functional disorders in the dentoalveolar apparatus. To study the morphological structure of enamel, its features depending on the presence and type of cervical pathology; to determine correlations of the chemical composition of enamel and dentin in intact teeth and with cervical pathology.

Material and methods
There were examined 29 clinically extracted teeth of both jaws and their longitudinal sections using a JSM-6490 LV focused beam electron microscope with system of energy-dispersive X-ray microanalysis. The chemical composition of 290 enamel areas and 235 dentine areas in the incisal region (tubercle), equator, cervical area.

Results
The correlation between enamel and dentin has been determined: inverse – based on the content of P and C, Ca and O (in all anatomical areas), Mg and Ca, Mg and P (in the incisal region (tubercle), equator); direct – based on the content of Mg and Ca, Mg and P (cervical area). The exception was the correlation between Mg and Ca in the incisal region (tubercle) in the group of the teeth with cervical pathology (r = 0.363), Ca and O in the cervical area in the group of the teeth with cervical caries and clinically intact hard tissues (r = 0.620).

Conclusions
The revealed features in the morphological structure and chemical composition of enamel, the presence of the correlations with dentin will allow to understand the mechanism of the development of cervical pathology deeper and substantiate the principles of its treatment and prevention.