[Study of clinical and histological features in professional teeth whitening]

The aim of the study was to study clinical and histological changes in the treatment of discoloration using different systems for professional tooth whitening. The study involved 76 patients. Patients of group 1 had their teeth whitened by the Amazing White Universal Extra photochemical activation system, and group 2 had their teeth whitened by the Beyond Polus system. Each group was divided into 3 more subgroups depending on the method of remineralization and the applied toothpaste (SENSITIVE ULTRA and SENSODYNE Rapid Relief). To assess teeth hyperesthesia before, immediately after and 14 days after the bleaching procedure, we used the prevalence index of teeth hyperesthesia, the intensity index of teeth hyperesthesia, and the Schiff sample. We also used a digital rating scale for patients. 100 teeth extracted for orthodontic indications were subjected to histological examination. The occurrence of hyperesthesia of teeth during professional bleaching was revealed in 100% of cases. Significant structural changes were registered in the enamel and dentin of the teeth, most pronounced during photo-whitening. The treatment based on zinc-substituted hydroxyapatite carbonate in combination with laserophonophoresis against the background of use the toothpaste SENSODYNE Rapid Relief had the greatest remineralizing effect.

The Forest Observation System, building a global reference dataset for remote sensing of forest biomass

Forest biomass is an essential indicator for monitoring the Earth's ecosystems and climate. It is a critical input to greenhouse gas accounting, estimation of carbon losses and forest degradation, assessment of renewable energy potential, and for developing climate change mitigation policies such as REDD+, among others. Wall-to-wall mapping of aboveground biomass (AGB) is now possible with satellite remote sensing (RS). However, RS methods require extant, up-to-date, reliable, representative and comparable in situ data for calibration and validation. Here, we present the Forest Observation System (FOS) initiative, an international cooperation to establish and maintain a global in situ forest biomass database. AGB and canopy height estimates with their associated uncertainties are derived at a 0.25 ha scale from field measurements made in permanent research plots across the world's forests. All plot estimates are geolocated and have a size that allows for direct comparison with many RS measurements. The FOS offers the potential to improve the accuracy of RS-based biomass products while developing new synergies between the RS and ground-based ecosystem research communities.

[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.