[Effect of bleaching on the biochemical composition of oral fluid and dental hard tissues structure]

The aim of the study was to study the influence of a number of whitening systems on the biochemical composition of the oral fluid and the histological structure of hard tooth tissues. The study included 129 patients aged 20 to 40 years who underwent a procedure for professional teeth whitening. Patients were divided into three groups, depending on the system used for teeth whitening; each group, in turn, was divided into three subgroups, depending on the remineralizing drug used after the bleaching procedure. All subjects underwent biochemical examination of the oral fluid prior to the procedure for professional teeth whitening, immediately after double bleaching, after remineralizing therapy and 14 days later in order to study the dynamics of calcium ion concentration changes, which was carried out with the help of an ion-selective electrode. Also 44 teeth were selected, which were divided into three groups of 11 teeth each, which were bleached in vitro. Other 11 teeth were included in the control group. The greatest excess of calcium ions in the oral fluid during tooth whitening was detected, the maximum excess was observed with the use of the photobleaching system, the lowest value of calcium ions was observed with the use of a system of teeth whitening with chemical activation. Remineralizing therapy after tooth whitening promoted a change in the level of calcium in the oral fluid, led to a decrease in the level of calcium in all groups of subjects. The use of the drug based on zinc-substituted hydroxyapatite carbonate Stomysens had the greatest remineralizing efficacy. When studying the histological structure of enamel and dentin after the bleaching procedure, significant morphological changes were revealed in the form of formation of cavity structures in enamel and dentin, as well as partial enamel separation.