References: 1. Borovsky E.V., Leontiev V. K Biologija polosti rta [Biology of the oral cavity]. Moscow, Medical book, N. Novgorod, Publishing house of the ngma, 2001, 304 p. 2. Gazhva S.I., Zhulev E.N., Progressive D.A., Rostov A.V. [Evaluation of microstructure changes in the topography of the enamel and its microhardness, depending on the influence of different bleaching systems]. Sovremennye problemy nauki i obrazovanija = Modern problems of science and education, 2015, no. 2, part 3, pp. 14 20. (In Russ.) 3. Krikheli N.I. Otbelivanie zubov i mikroabrazija jemali v jesteticheskoj stomatologii. Sovremennye metody [Teeth whitening and enamel microabrasion in aesthetic dentistry. Modern methods]. Moscow, publishing house of Practical medicine, 2008, pp. 191 204. 4. Uspenskaya O.A., Shevchenko E.A., Kazarina N.In. [Dentistry pregnant Methodical recommendations]. Zhurnal mikrobiologii, jepi demiologii i immunobiologii = Journal of Microbiology, epidemiology and Immunobiology, 2009, no. 2, pp. 101 103. (In Russ.) 5. Terehova N.V. Klinicheskaja jeffektivnost' otbelivanija vital'nyh zubov // Stomatologicheskij zhurnal. – 2011. – №3. – S.221–224. 6. Hayward R., OsmanY., Grobler S.R. Aclinical study of the effectiveness of a light emitting diode systems on tooth bleaching // Open Dent J. – 2012. – №6. – Р.143–147. 7. Haywood V.B. Commonly asked questions about nightguard vital bleaching // Dent-Assist. – 1996. – Vol.65, N2. 8. Li Y., Greenwall L. Safety issues of tooth whitening using peroxide-based materials // British Dental Journal. – 2013. – Vol.2156, N1. – P.29–34. 9. Marshall K., Berry T.G., Woolum J. Tooth whitening: current status // Compend. Contin. Educ. Dent. – 2010. – Vol.31, N7. – P.486–492, 494–495.

Abstract Subject. Whitening techniques do not exclude the occurrence of undesirable consequences for tooth tissues after the whitening procedure. The study of the effect of a whitening agent on the hard tissues of the teeth and the elimination of complications remains an important and urgent issue. As a result of whitening, not only the discoloration of the organic component of the hard tissues of the teeth occurs, but also its partial death, which is expressed in the expansion of the enamel tubules and the change in the hydrodynamic processes in the tooth enamel.