The influence of silicon compounds on the processes of formation and development of natural bone tissue is considered, the concentration of silicon compounds in various tissues of organs is given. The inducing effect of various implantation substrates with silica content on the vital activity of osteogenic cell cultures is described. It is assumed that the processes of binding of bone tissue to silicate implantation material are influenced by the presence of a significant number of silanol groups on the surface of the material, which determine its high hydrophilicity. It is shown that the solubility of silicate glasses depends on the presence in their composition of a phase corresponding to the composition of liquid glass, and its role in the process of material biodegradation in physiological media is described. Table 1, bibliography: 14 titles.
The properties of hydroxyapatite (HAP) powder synthesized from calcium chloride and potassium hydrogen phosphate have been investigated. The powder material consists of HAP and a by-product containing predominantly KCl. After firing at temperatures above 800 ° C, the ceramics contains HAP as the main phase, as well as CaO and chlorapatite. The maximum density (2.2 g / cm 3 ) and the minimum grain size (200 - 500 nm) are observed in the material after firing at a temperature of 700 ° C. Il. 6, bibliography: 7 titles.
The main difficulty in the manufacture of hydroxyapatite-based ceramic materials is their high sintering temperature. Potassium feldspars, low-melting leucite glass, and synthetic alkali-containing compounds were studied as compounds that increase the amount of melt to improve the sintering process. The influence of alkali-containing additives on the processes of phase formation during sintering of compositions based on hydroxyapatite-fluorite mixtures is considered. Tab. 2, ill. 7, bibliography: 5 titles.
The possibilities of producing ceramics from nanodispersed powders of silicon dioxide and hydroxyapatite have been investigated. The obtained ceramics with a fine-grained (3 - 10 ?m) structure. The properties of the initial nanopowder and ceramics have been studied by transmission and scanning electron microscopy and X-ray phase analysis. The glassy materials obtained from tarkosil (silicon oxide) powder are transparent in the ultraviolet range. Strong ceramic samples of hydroxyapatite with a grain and pore size of 1 ?m or less were obtained with open porosity uniformly distributed over the volume. The results of the study can be useful in the design of medical implants based on hydroxyapatite and ceramic membranes with controlled porosity. Il. 3, bibliography: 8 titles.
The results of obtaining ceramic elastic-rigid and elastic-elastic capillary-porous structures are presented and the possibility of their modification into thin-layer semipermeable membranes with filtration properties is investigated. It has been established that the most effective technological methods for the manufacture of ceramic membranes based on spondyloid clay and calcium-phosphate materials are semi-dry multistage pressing of initial powders and casting from suspensions. A comparative study of elastic-rigid membranes of two main compositions was carried out, the presence of a capillary-porous structure and the proximity of the values ??of their gas permeability and filtration rate were established. The study of elastoelastic resorbable and semi-resorbable membranes based on biogenic hydroxyapatite showed that they are promising for use in medicine. Tab. 2, bibliography: 6 titles.
The main methods of obtaining porous vitreous and glass-crystalline materials are considered and analyzed by the example of bioactive materials for bone endoprosthetics. The possibility of using the sol-gel technology for the formation of porous structures according to the developed 3D model is shown. Tab. 1, ill. 2, bibliography: 9 titles.
An overview of methods for the manufacture of porous materials is given. The optimal methods for the manufacture of porous materials based on calcium phosphates, including those for use as bone implants, are shown. Bibliography: 20 titles.
It has been shown that the K 2 O - Al 2 O 3 - SiO 2 system is promising for the production of glass ceramics containing leucite and intended for the manufacture of dentures. Glass formation in this system and the crystallization ability of glasses, including those modified with Li 2 O and Na 2 O, have been studied. The influence of temperature-time parameters on liquation and crystallization processes has been studied. Tab. 1, ill. 3, bibliography: 2 titles.
The study of the influence of the composition of calcium silicate glasses on the behavior of powders of different dispersion (500, 60 and 10 microns) in an aqueous medium has been carried out. The acid-base characteristics of the aqueous medium and the concentration of calcium ions in the aqueous solution after holding the glass powders have been determined. It is shown that the main parameter determining the mechanism of glass dissolution in water is their basicity modulus. Tab. 2, ill. 2, bibliography: 4 titles.
The properties of hydroxyapatite powder synthesized from calcium acetate, hydrogen phosphate, and potassium hydroxide have been investigated. A by-product of the reaction (SPR), the main component of which is potassium acetate, modifies the surface of hydroxyapatite nanocrystallites. The SPR components can play the role of a salt matrix, preventing the fusion of nanocrystallites, and can also serve as a source of a sintering additive, the uniform distribution of which occurs due to adsorption during synthesis. Thanks to the introduction of a sintering additive in the form of a SPR at a temperature of 700 ° C, a hydroxyapatite-based ceramic with a homogeneous microstructure and a grain size of no more than 300 nm was obtained. SPR is the reason for the occurrence of various solid-phase processes and processes with the participation of the liquid phase. The place of occurrence of such processes is the grain boundaries, which inhibits their growth. Tab. 1, ill. 7, bibliography: 6 titles.
