Morphological structure of enamel caries in the dynamic process of demineralization and remineralization

Abstract

According to modern ideas, the carious process at the white spot stage is reversible, so all the attention of scientists is directed to the development of means to restore the crystal lattice of tooth enamel. The purpose of the study is to evaluate morphological changes in caries at the white spot stage and the process of structural remineralization of the carious lesion area. Clinically active initial lesions were detected visually, using optical magnification and positive staining. Structural changes in enamel were studied by scanning electron microscopy of surface impressions obtained from the surface of demineralized enamel. Remineralizing therapy was carried out by applying ApaCare restorative gel (Germany) with nanodispersed highly active hydroxyapatite. Determination of the intensity of dental caries by the DMFT and dmft index showed 9.04 ± 0.40 points on average in the group of subjects, children with code 1 according to the ICDAS index made up 50.8%. Colour reactions showed 7.80 ± 0.21 points on average in the group. SEM visualized characteristic structural changes in the area of the carious spot – an increase in the porosity of the enamel surface with exposure of the fine crystalline structure and destruction of interprismatic fibrillar structures. When using a remineralizing agent, a roller-like deposition of an amorphous remineralizing substance is characteristic, and at the final stage, a smooth enamel surface with a fine crystal lattice is restored. The restoration of the prismatic structure of the enamel occurs due to the mineralization of the preserved fibrillar walls in the interprismatic space. Clinically, at this stage, the enamel visually restores its original shine, smoothness, and colour. In 81.8% of cases, the dye did not penetrate the previously demineralized enamel. The high level of non-cavitated active caries lesions can be largely controlled by the use of remineralizing agents. Further research involves studying the quantitative characteristics of the processes of de- and remineralization of tooth enamel.