[Physiological changes in the morphology of the main structural enamel unit - hydroxyapatite crystal - during its life span (in vitro study)].

The in vitro study by means of complex laboratory techniques including X-ray faze analysis, infrared spectroscopy, scanning electron and atomic force microscopy defined age-related physiological mineralization process as a shift of the structural enamel unit - nanocrystalline hydroxyapatite crystals - TO microcrystal phase. Relevant anatomical sites with age-dependent enamel optical characteristics corresponding to certain ratio of hydroxyapatite phases and the compliance of their color characteristics to composites enamel layers were revealed.