Репозиторий Университета

© 2020 Elsevier B.V. A critical-sized calvarial defect in rats is employed to reveal the osteoinductive properties of biomaterials. In this study, we investigate the osteogenic efficiency of hybrid scaffolds based on composites of a biodegradable and biocompatible polymer, poly(3-hydroxybutyrate) (PHB) with hydroxyapatite (HA) filled with alginate (ALG) hydrogel containing mesenchymal stem cells (MSCs) on the regeneration of the critical-sized radial defect of the parietal bone in rats. The scaffolds based on PHB and PHB/HA with desired shapes were prepared by two-stage salt leaching technique using a mold obtained by three-dimensional printing. To obtain PHB/HA/ALG/MSC scaffolds seeded with MSCs, the scaffolds were filled with ALG hydrogel containing MSCs; acellular PHB/ALG and PHB/ALG filled with empty ALG hydrogel were prepared for comparison. The produced scaffolds have high porosity and irregular interconnected pore structure. PHB/HA scaffolds supported MSC growth and induced cell osteogenic differentiation in a regular medium in vitro that was manifested by an increase in ALP activity and expression of the CD45 phenotype marker. The data of computed tomography and histological studies showed 94% and 92%, respectively, regeneration of critical-sized calvarial bone defect in vivo at 28th day after implantation of MSC-seeded PHB/HA/ALG/MSC scaffolds with 3.6 times higher formation of the main amount of bone tissue at 22–28 days in comparison with acellular PHB/HA/ALG scaffolds that was shown at the first time by fluorescent microscopy using the original technique of intraperitoneal administration of fluorescent dyes to living postoperative rats. The obtained in vivo results can be associated with the MSC-friendly microstructure and in vitro osteogenic properties of PHB/HA base-scaffolds. Thus, the obtained data demonstrate the potential of MSCs encapsulated in the bioactive biopolymer/mineral/hydrogel scaffold to improve the bone regeneration process in critical-sized bone defects.

The purpose of the study was to assess the impact of toothpastes containing hydroxyapatite and fluoride on enamel caries resistance and remineralization rate. Study groups comprised 160 patients divided in 2 groups of 80 patients: 40 - at the age of 15-17 and 40 at the age of 18-25 who have been using toothpastes with hydroxyapatite and fluoride during 1 year. The plaque determination was carried out with the use of OHI-S and Turesky indexes. Litmus test pieces were used to determine oral fluid pH. The clinical determination of enamel remineralization rate, dynamics of acid resistance of enamel were carried out. Oral hygiene at baseline examination was poor in both groups. After oral hygiene training, there was a tendency towards indexes decrease more pronounced in the 18-25 age group regardless of the composition of the toothpastes used. Mean baseline oral fluid pH in the observation group was 6.5±0.4, in the comparison group - 6.8±0.4. By the end of the trial there was a tendency towards the increase of the oral fluid pH, which were 7.3±0.3 and 7.7±0.3, respectively. The enamel acid resistance of the patients of the observation group was significantly higher (p>0.05) compared with the group of patients using fluoride toothpaste, as well as the proportion of patients in whom the enamel recovery occurred within 24 hours (47.5% vs. 22.5%, respectively).

The purpose of our study was to assess the efficiency of toothpaste 'Intensive strengthening of supersensitive teeth with nano-GAP' INNOVA and the suspension 'Liquid Enamel' INNOVA on the sensitivity of teeth with gingival recession. We examined 40 people aged 20-25 years. Each group consisted of 20 people: 10 women, 10 men. The first group (observations) used the paste and the suspension for 14 days, and the second group (comparisons) cleaned teeth only with a brush without a paste. Schiff aerial test was performed to assess the rate of hypersensitivity. As a result of the study, it was found that the combination of paste and liquid suspension with nano-hydroxyapatite for 14 days effectively reduced the hypersensitivity of the teeth with gingival recession that was shown by a statistically significant decrease in the Schiff index in the observation group. Thus, this combination is the method of choice in the treatment of hyperesthesia and can be used as an alternative substitute therapy.

Проведен анализ научной литературы за период с 1991 по 2016 г., посвященной хирургической подготовке костной ткани челюстей к дентальной имплантации путем применения синтетических остеопластических материалов. Подбор научной литературы проводился в Центральной научной медицинской библиотеке, электронной медицинской библиотеке eLIBRARY.RU, а также по базе данных медицинских публикаций PubMed. В обзоре проанализированы результаты экспериментальных и клинических исследований особенностей и эффективности применения таких материалов, сроки их замещения на новообразованную костную ткань, а также эффективность применения синтетических заменителей и других видов остеопластических материалов.

Проведен анализ научной литературы за период с 1991 по 2016 г., посвященной хирургической подготовке костной ткани челюстей к дентальной имплантации путем применения синтетических остеопластических материалов. Подбор научной литературы проводился в Центральной научной медицинской библиотеке, электронной медицинской библиотеке eLIBRARY.RU, а также по базе данных медицинских публикаций PubMed. В обзоре проанализированы результаты экспериментальных и клинических исследований особенностей и эффективности применения таких материалов, сроки их замещения на новообразованную костную ткань, а также эффективность применения синтетических заменителей и других видов остеопластических материалов.