Silicon-hydroxyapatite‒glycerohydrogel as a promising biomaterial for dental applications.

Nanocomposite silicon-hydroxyapatite‒glycerohydrogel (Si-HA‒glycerohydrogel) with different hydroxyapatite (HA) contents of 0.75 and 1.75 wt.% and the same Si content (2.04 wt.%) was obtained by the sol‒gel method. Silicon tetraglycerolate in the form of glycerol solution was used as a biocompatible precursor and HА in the form of aqueous colloidal suspension - as a template and property modifier. Transmission electron microscopy was applied to demonstrate that there are nanoscale HA particles that are in the crystalline state. For the first time, using the atomic force microscopy method, the remineralizing properties of Si-HA‒glycerohydrogel were studied on human teeth extracted for orthodontic reasons. It was found that Si-HA‒glycerohydrogel containing 1.75 wt.% HA has a pronounced remineralizing effect. Immersion of tooth enamel samples in the gel for one month significantly reduces roughness and makes the enamel surface more uniform. Silicon contained in glycerolates in a biologically active and accessible form exerts an additional positive effect on the process of remineralization of tooth enamel. By the energy dispersive X-ray analysis, it was demonstrated that the tooth enamel had an increased silicon content; and the Vickers microhardness test showed greater microhardness values. The obtained data analysis allows the remineralizing Si-HA‒glycerohydrogel to be considered as a promising biomaterial for dental applications.

[Development and evaluation of simulation methods for manual skills training in 'Removable dentures' module]. / Razrabotka i otsenka éffektivnosti simuliatsionnoi metodiki obucheniia manual'nym navykam po moduliu 'Nes''emnoe protezirovanie.

To determine the effectiveness of a simulation method of teaching manual skills modulo 'removable dentures' in a clinical setting. MATERIAL AND METHODS: The material 1 phase of the study were 82 people, students of 3 courses, divided into a control group where the training was conducted with the use of standard phantoms and group study which used a dental simulator CDS 100 of V generation. Material 2 stages presented 48 people who participated in phase 1 and divided into groups similar to the 1 stage, young professionals in 2016. An objective assessment of the quality of preparation for 2 stages made with a scanner Zirkozahn arti s600. RESULTS: In the control group, the main reason for the need for additional correction of the abutment teeth as 1 and 2 is the inadequacy of stage periodontal ledge factor ANOVA with the indicator 1.1 for one phase of the study and 1.15 for 2 stages, indicating that the statistical predictors in this group identity. The group studies found no statistically significant difference in the quality of the executed periodontal ledges 1 and 2 stages of the study, 0.9-way ANOVA factor, which indicates the statistical significance of the predictor as pre-acquisition movements automatism acquired while working with the simulator. CONCLUSION: The use of an interactive computer simulation CDS 100 provides a higher level of acquisition, and the main 'survival' of practical skills, confirmed by subsequent clinical practice, compared with the classical form of education.

[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.