Ceramic based on zirconium dioxide (ZD) is a modern, durable material for the manufacture of dentures. It is known that ZD is not etched as glass-ceramic, making it difficult to prepare this material before fixing.OBJECTIVE:To study the impact of various methods of surface treatment of ZD-based ceramic on adhesive strength.MATERIALS AND METHODS:Sandblasting with Al2O3 particles sized 50 μm and application of primers with 10-MDP phosphate monomer were used. Adhesive strength values for following 4 groups of samples were obtained: 1st group - RelyX U200 + sandblasting + Compofix new primer (n=9); 2nd group - Compofix + sandblasting + Compofix new primer (n=9); 3rd group - Panavia F 2.0 + sandblasting (n=9); 4th group (control) - Variolink Esthetic DC + sandblasting + Monobond Plus primer (n=9).RESULTS:The highest strength of adhesion was in the 4th group - 48.71±5.71MPa, the smallest in the 3rd group - 9.49±35.24 MPa. Fully domestic components used in the 2nd group allowed to obtain values of 42.50±9.79 MPa. Adhesive strength in the 1st group was 34.11±4.78 MPa.CONCLUSION:The absence of the 10-MDP-based primers application in the preparation of ZD ceramic reduces the adhesive strength between resin cement and its surface. The domestic set for fixation of dentures can be effectively used for ZD on the same basis as European analogue.

The influence of the modification of glass in the strontium-aluminum-boron-silicate system (SABS) on technological and physicochemical properties was investigated. Introducing two alkalis into the glass makeup significantly lowered the melting temperature, from 1500 to 1450°C, which effected changes in the properties of the glass. On introducing alkalis in amounts up to 5 mol.

The influence of boron oxide additives in amounts 0 to 11 mol.

Glasses were obtained in the SiO2–Al2O3–SrO–P2O5–F system with a phosphorus oxide content in the range of 7 – 12 mol. %. The set of properties of the obtained glasses (refractive index 1.514 – 1.535, TCE 44?10–7 – 61?10–7 K–1, transmittance above 85 %, radiopacity not less than 300 %) in the aggregate with the processability of synthesis (melting temperature below 1500 ?C) indicates that they are promising candidates for use as fillers of glass ionomer cements for dentistry.

A new glass-filler for dental composites has been developed based on glass in the system SrO–Al2O3–B2O3–SiO2. This filler meets contemporary requirements for filling materials and is characterized by high chemical resistant to water, acids and alkalis (Class I), high visible-range transparency (> 80

new glass-filler for dental composites has been developed based on glass in the system SrO–Al 2 O 3 –B 2 O 3 –SiO 2 . This filler meets contemporary requirements for filling materials and is characterized by high chemical resistant to water, acids and alkalis (Class I), high visible-range transparency (> 80%), and CLTE-compatibility with the polymer matrix. The melting temperature is acceptable, and crystallization is not a proclivity. It is shown [demonstrated that the new glass filler effects high-level medical-biological, operational, and functional properties of the dental composite based on it, and competitiveness with respect to the popular foreign-made analog materials.

A silver-containing gel based on polyvinyl alcohol and aryloxycyclotriphosphazene containing β-carboxyethenylphenoxy and p-formylphenoxy groups has been developed. Phosphazene was synthesized via the Doebner reaction from hexakis[(4-formyl)phenoxy]cyclotriphosphazene and malonic acid and characterized by 1H, 13C, and 31P NMR spectroscopy and MALDI-TOF mass spectrometry. The study of the gel using scanning electron microscopy showed that the gel contains open pores and can absorb wound exudate. The maximum water absorption capacity of the gel was 272%, which was reached after 80 min of testing. The antimicrobial activity of the obtained silver-containing gel was evaluated using the diffusion method. The gel was found to inhibit the growth of the main microorganisms in contact with the skin: the bacteria S. aureus, P. aeruginosa, E. coli, B. subtilis, S. epidermidis, and C. stationis and the fungus C. albicans. The study of the wound-healing effect of the gel in vivo showed a decrease in the wound area of the rabbit hind limb by 91.43% (p < 0.05) on the 10th day of observation and a decrease in the content of C-reactive protein in the rabbit blood serum by 1.3 times (p < 0.05).

Dental composite ?lling materials based on glass in the SrO–Al2O3–B2O3–SiO2 system was obtained. The glass filler meets the modern level of requirements for filling materials, and is characterized by high chemical resistance to water, acids and alkalis (class I), high transparency (more than 80 %), consistency with the polymer matrix according to CTE while maintaining of an acceptable melting temperature and no tendency to crystallization. It is shown that the developed glass filler provides a high level of biomedical, operational and functional properties of a dental composite based on it and competitiveness with respect to popular foreign analogue materials.

Предложен усовершенствованный способ изготовления стоматологического бора с упрочненными эксплуатационными характеристиками, с добавлением в технологию этапа электрохимического травления нанесенного рабочего слоя и введением упрочняющего каркасного слоя абразива, что дает значительное преимущество по производительности в сравнении со стандартным бором.

The article presents the results of the elaboration of techniques for identification and assay of a new active pharmaceutical substance (API) – 3- (1H-benzimidazol-2-yl) -1,2,2-trimethylcyclopentane-carboxylic acid. To identify the API, the method of IR spectroscopy was used, the assay was carried out using the method of direct acidimetric titration in a medium of glacial acetic acid. Methods were validated in accordance with the requirements of the State Pharmacopoeia of the Russian Federation and are suitable for further use in quality control in the production of 3- (1H-benzimidazol-2-yl) -1,2,2-trimethylcyclopentane-carboxylic acid.

The reaction of epoxyphosphazenes with methacrylic acid was used to synthesize methacrylate-containing phosphazene oligomers (MPO) used to modify dental restorative materials.The introduction of 1015 wt.% MPO into the base bis-methacrylate binder composition can significantly increase the adhesion of modified cured compositions to tooth tissues and metals, as well as improve water resistance while maintaining the required strength indicators and other physicochemical characteristics required by GOST.

The aryloxyphosphazenes containing carboxylic groups in phosphorus-linked radicals and capable of copolymerization with acrylic binders were used as modifiers of dental polymer compositions. Filled modified dental compositions have been obtained and tested. It has been shown that the best mechanical and physicochemical parameters are exhibited by cured compositions with a modifier based on aryloxyphosphazene with 4-hydroxycinnamic and eugenol radicals in the phosphazene ring.

The effect of boron oxide additives in the amount from 0 to 11 mol. % was studied on the melting characteristic of glasses in the SrO–Al2O3–TiO2–ZrO2–B2O3–SiO2 system for use as fillers in dental filling composites in order to reduce the melting temperature to technologically acceptable values (no more than 1500 ?C) and increase the transparency of the produced granulate. It was found that with an increase in the B2O3 content, the melting temperature can be reduced from 1600 ?C (in glasses without B2O3 additives) to 1480 ?C with a B2O3 content of 11.8 mol. %, while the glass transition temperature decreases from 820 to 743 ?C. Already with a B2O3 content of 6 mol. % at a melting temperature of 1500 ?C, transparent glasses with light transmission of 80 % are produced, promising for the creation of sealing composites.

Based on glass in the SrO–Al2O3–P2O5–SiO2–F system, functional glass fillers for glass ionomer cements containing up to 13 wt. % fluorine were obtained. The high level of radiopacity of the filling material is due to the presence of the absorbing component of the glass filler - oxide and strontium fluoride, which are introduced into the glass together. The use of fusible fluorine-containing raw materials makes it possible to reduce the glass transition temperatures, which opens up prospects for the industrial development of the developed compositions at melting temperatures below 1500 °C. The value of the refractive index of glasses with a high fluorine content nD ~ 1.50 is more in line with the refractive index of the polymer matrix of glass ionomer cement, which ensures high aesthetic characteristics of the filling material. Samples of transparent filling glass ionomer cement with high compressive strength > 100 MPa and hardening time of 5 min were obtained.

Л.В., 1,2 Чуев В.П., 1 Афонин А.Н.

This review aims to describe and critically analyze studies published over the past four years on the application of polymeric dental nanomaterials as antimicrobial materials in various fields of dentistry. Nanoparticles are promising antimicrobial additives to restoration materials. According to published data, composites based on silver nanoparticles, zinc(II), titanium(IV), magnesium(II), and copper(II) oxide nanoparticles, chitosan nanoparticles, calcium phosphate or fluoride nanoparticles, and nanodiamonds can be used in dental therapy and endodontics. Composites with nanoparticles of hydroxyapatite and bioactive glass proved to be of low efficiency for application in these fields. The materials applicable in orthodontics include nanodiamonds, silver nanoparticles, titanium(IV) and zinc(II) oxide nanoparticles, bioactive glass, and yttrium(III) fluoride nanoparticles. Composites of silver nanoparticles and zinc(II) oxide nanoparticles are used in periodontics, and nanodiamonds and silver, chitosan, and titanium(IV) oxide nanoparticles are employed in dental implantology and dental prosthetics. Composites based on titanium(IV) oxide can also be utilized in maxillofacial surgery to manufacture prostheses. Composites with copper(II) oxide nanoparticles and halloysite nanotubes are promising materials in the field of denture prosthetics. Composites with calcium(II) fluoride or phosphate nanoparticles can be used in therapeutic dentistry for tooth restoration.

The asymmetric unit of the title compound, sodium 2-[1-methyl-5-(4-methylbenzoyl)-1H-pyrrol-2-yl]acetate dihydrate, Na+·C15H14NO3−·2H2O, contains two sodium cations, two organic anions (A and B) and two water molecules. The coordination geometry around the sodium cations corresponds to a distorted octahedron. Each pair of sodium cations (A–A or B–B) is chelated by two bridging anions coordinated by the O atoms of the deprotonated carboxylic groups, and each sodium atom is coordinated by an O atom of a third anion, which connects pairs of sodium atoms, and a water molecule. As a result, a two-dimensional polymer is formed in the crystal. Hirshfeld surface analysis and two-dimensional fingerprint plots were used to analyze the intermolecular contacts present in the crystal.

Introduction: The aim of the present study was to research the analgesic activity and effect of new dipharmacophore compounds consisting of substances with proven therapeutic activity, namely nebracetam–ibuprofen (NRIP), nebracetam–dexibuprofen (NRDIP), nebracetam–niflumic acid (NRNFA), and nebracetam–mefenamic acid (NRMFA), on the cognitive abilities of rats. Materials and methods: The experimental study was performed in 110 Wistar rats (male/female ratio 50/50%), weighing 180–200 g, and 50 laboratory mice (male/female ratio 50/50%) weighing 18–22 g. The study of the analgesic activity was carried out using the acetic acid writhing test and the hot plate test. The effect on the cognitive abilities of rats was studied using the pattern recognition test in a model of neurotrauma caused by a drop-weight. Results and discussion: It has been shown that the administration of dipharmacophores nebracetam–ibuprofen (NRIP), nebracetam–dexibuprofen (NRDIP), nebracetam–niflumic acid(NRNFA) as well as nebracetam–mefenamic acid (NRMFA) in the tested dosages leads to a statistically significant (p<0.05) analgesic action in acetic acid writhing tests and hot plate tests. At the same time, the analgesic activity of the compounds has been shown to conjoin with a statistically significant influence on cognitive functions in the experimental animal groups after simulating a neurotrauma. Conclusion: The dipharmacophore compounds studied in the present research, having analgesic and nootropic effects, can be used as effective and safe analgesics and can also be used for the treatment and prevention of pain syndrome, enhancing the cognitive abilities of healthy people in complicated professional conditions.