Эндодонтия Today (Mar 2020)
Morphological changes in enamel and dentin resulting from the bleaching of teeth
Abstract
Relevance of the research topic: modern bleaching systems are based on the use of hydrogen peroxide preparations or carbamide peroxide, in combination with activating factors. Hydrogen peroxide acts as a strong oxidant by the formation of free radicals, reactive oxygen molecules and hydrogen peroxide anions. Many researchers believe that the discoloration of tooth whitening is determined primarily by changes in the dentin. Others dispute the idea of color change in dentin and believe that it occurs only in enamel, masking unchanged dentin. Objective: to study histological changes in the structure of hard tooth tissues during whitening. Materials and methods: 12 intact teeth removed by orthodontic indications after in vitro bleaching procedure and 4 intact teeth not subjected to the bleaching procedure were selected. To whiten teeth, a system was used that included a gel based on 24% hydrogen peroxide (Amazing White Professional). After the bleaching procedure, histological preparations were made and the study was carried out using a microscope mVIZO-101 (OJSC LOMO, Russia). Results: the surface of the enamel after bleaching had a significant number of wedge-shaped defects, as well as a slight delamination. In the upper and middle third of the enamel, cavity changes in the form of pores in a significant amount were observed. The dentinal tubules were enlarged, the location was not traced. Conclusions: a single photochemical bleaching procedure leads to significant morphological changes in the structure of hard tissues of the teeth, which manifest themselves as wedge-shaped defects in the enamel, as well as the appearance of cavities in the enamel-dentine border and the heterogeneity of dentin with a significant number of pores.
