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Biomedical subjects

A I Volozhin

Publications and source records attributed to A I Volozhin.

At least 37 records · Page 2Linked to original sources
PubMed2001

[Questions on the efficiency of membrane technology in treating periodontal diseases. Experience of experimental and clinical studies].

Experimental and morphological studies demonstrated that Gore Resolute resorbable membrane can cause local inflammatory reactions similar to allergic. Collagen-based biomembranes coated with hydroxyapatite cause no local pathological reactions, but are rapidly resorbed in foci of degeneration under the effect of aggressive factors of tissue environment. Russian silicone membrane has been clinically tried with satisfactory results in patients with generalized periodontitis; the results prompt further studies of the membrane.

Biocompatible Materials↗
PubMed2001

[Volatile compounds in air and oral saliva in healthy people, and in periodontitis and gingivitis patients].

21 healthy persons, 7 patients with chronic generalized periodontitis and 4 patients with chronic generalized gingivitis aged between 18 and 42 years were examined. Air from the oral cavity was collected with a special device; liquid samples were collected by washing the oral cavity with sterile water. Chemical compounds of the air and the washed liquid were analyzed by chromato-mass-spectrometry, gas-adsorption and gas-liquid chromatography. The content of dimethyl sulphide, dimethyl disulphide increased in the oral air and such volatile short chain fatty acids (VSCFA) as butyrate, propionate, acetate rose, but their aldehydes (butyraldehyde, acrolein, acetaldehyde decreased in oral fluid during periodontitis. The concentration of these compounds were found to be between the levels in control persons and during periodontitis. The content of pentane decreased in oral air. That depended on the intensity of inflammation and vessel disturbances. The results suggest that VSCFA produced by Porphyromonas, Prevotella, Fusobacterium and other periodontopathic bacteria, penetrate the oral mucosa and severely harm the periodontal tissue. The increase of dimethyl sulphide contributed to oral malodor during periodontal inflammation.

Adolescent↗
PubMed2001

[Role of phagocytosis activation in the mechanism of therapeutic effect of medical ozone in patients with sluggish purulent inflammations of maxillofacial soft tissues].

Sixty-three patients with local sluggish suppurative inflammations of maxillofacial soft tissues were examined. Medical ozone was added to the treatment protocols of 30 of these patients. Before treatment peripheral blood leukocyte phagocytic activity was decreased in 54 patients, which corresponded to clinical form of a sluggish inflammation. Traditional therapy did not appreciably change the level of phagocytosis. Addition of medical ozone exposure to therapy promoted normalization of leukocyte phagocytic activity and accelerated liquidation of inflammation.

Adolescent↗
PubMed2000

[The evaluation of periodontal status by the chemical composition of the oral media].

Twelve patients aged 21-38 years with gingivitis and periodontitis and 9 subjects with intact periodontium were examined. Air from the oral cavity was collected with a special device, liquid samples were collected by gargling with sterile water. Chemical composition of the air and washings was analyzed by chromato-mass-spectrometry, gas adsorption and gas liquid chromatography. Inflammation of periodontal tissues was associated with a sharp increase in the oral air concentration of methylethylketone. The concentrations of isovaleric, n-valeric, and n-enanthic aldehydes increased appreciably. Ethanol predominated over n-butyl alcohol. The levels of dimethylsulfide and isoprene increased several times. In the washings from the oral cavity, the content of microorganism's vital activity products (fatty acids) was increased. Possible metabolic mechanisms of the detected shifts are discussed.

Adult↗
PubMed2000

[The osteoplastic efficacy of different forms of hydroxyapatite based on experimental morphological study data].

Time course of healing of induced defects in the femoral bone filled with various forms of hydroxyapatite (HA) was studied in experimental rats on days 30, 60, and 90 after inflicting the defect. HA granulate exerted the best effect on bone repair. In experiments with HA granulate, bone regenerate replaced up to one half of the area of defect by day 90. After insertion of a mixture of granulate and HA powder in bone defects the newly formed bone occupied a little more than one-third of the defect area. In experiments with HA powder suspension the size of bone defect by day 90 was the same as after healing under a blood clot.

Animals↗
PubMed2000

[Characteristics of tissue reaction upon implantation of injected polyacrylamide gel containing silver and hydroxyapatite].

Albino rats were subcutaneously injected with polyacrylamide gel (PAAG) (1 ml) with 20% distilled water, water with silver ions, and 1 and 3% hydroxyapatite (HAP), and tissue reaction was evaluated over 5-90 days postinjection. PAAG containing HAP and silver ions can be used for contour plastic repair of soft tissues; its use is particularly recommended for repair or modification of facial contours with one's own tissue.

Acrylic Resins↗
PubMed1999

[Social aspects of the adaptation and human ecology].

Influence of natural factors on humans or human migration into extreme conditions alters relationships between population and environment, therefore functional resources are mobilized. This alteration sometimes induces genotypic and phenotypic inadequacy to new, more strict requirements of natural and occupational factors. That is because evolution develops and genetically fixes in most people various mechanisms providing and supporting biologic balance. Requirements set in favorable environmental conditions for homeostatic systems including immune one are adequate to genotype of most individuals. When those mechanisms are not fixed and/or environmental conditions appear unfavorable the changes occur that could transform into disease.

Adaptation, Psychological↗
PubMed1999

[The syndrome of reduced colonization of periodontium tissues during long-term anti-orthostatic hypokinesia].

Effects of antiorthostatic hypokinesia (AOH, -6 degrees) during 60 and 120 days on the parodontium in 10 human subjects aged 24-33 yr. have been studied. Clinical, functional, immunologic, and microbiological analyses were performed 30 days prior to, on days 7 and 30, and on day 7 since the experiment. The parodontium was assessed by relevant indices, immunoglobulines in the oral fluid, and bacteriological parameters determined with the anaerobic cultivation technique. AOH was found to reduce the colonisation resistance of the parodontium due to obviously, the immunologic inertia and consequent changes in the qualitative composition of microflora. It is concluded that the parodontium responds to extreme conditions by replacement of the commensal microflora by opportunistic and obligate parodontosis pathogens.

Adult↗
PubMed1999

[A hypothetical model of the biomechanical interaction of the teeth and the abutment tissues of the jaws during masticatory loading of different values].

Biomechanical model "tooth-jaw" in considered. This biomechanical model takes into account local nonhomogeneous mechanical constructions tooth-jaw, its special geometry, physical properties of firm tissues of tooth, periodontium and jaw. Using mathematical methods, determination of supporting jaw tissues depending by computer tomograms was grounded. The system SPLEN-K has calculated tension-deformed condition of dental tissues in area of a group of chew teeth.

Biomechanical Phenomena↗
PubMed1999

[The dynamics of the healing of experimentally reproduced bone defects filled with different polyacrylamide gel-based compounds].

Time course of healing of standard osseous defects by introduction of polyacrylamide gel (PAG)-based materials was studied in rat experiments. PAG did not prevent the formation of soft-tissue and osseous regenerate in bone defects. Addition of hydroxyapatite, bactericidal agent, and lysozyme to PAG-based composition led in some cases to development of chronic inflammation and giant-cell reaction in osseous wound and to inhibition of the reparative processes.

Acrylic Resins↗
PubMed1998

[The tissue reaction to acrylic plastics modified by supercritical extraction with carbon dioxide].

The process of extraction of admixtures from acryl plastic widely used in dentistry by means of supercritical carbon dioxide (sc-CO2) was studied and effects of extraction conditions on biocompatibility and toxicity of resultant materials assessed, sc-CO2 effectively purified the specimens from toxic compounds (monomers and low-molecular oligomers, methylmethacrylate, dichloroethane) and notably improved the biocompatability of polymer implants. Tissue reaction to ethacryl and protacryl depends on the degree of implant polymerization and duration of extraction of toxic substances from polymer.

Acrylic Resins↗
PubMed1998

[The biomedical efficacy of 2 variants of polyacrylamide gel- and hydroxyapatite-based composite materials in the plastic repair of bone defects (experimental morphological research)].

Tissue status at the site of experimental bone defects filled by two compositions based on polyacrylamide gel and hydroxyapatite with (experimental group) and without (controls) lysozyme was studied in rats by the histomorphological method. "Negative" symptoms, such as inflammation, formation of osteocyte-free bone at the interface of the defect, and reduction of red bone marrow were more manifest in the controls than in animals treated with lysozyme. In the test group substitution of composite material for connective tissue structures and bone reparation were much more active and rapid than in the controls. Inflammation and dystrophic changes at the interface of defects were less pronounced and gradually resolved.

Acrylic Resins↗
PubMed1997

[Patterns of mercury release from amalgam fillings into the oral cavity].

Seventy-five subjects aged 20 to 57 with 1 to 15 fillings of silver amalgam were examined. The level of mercury vapors in the oral cavity was assessed using an AGP-01 device and the method developed by the authors. Emission of mercury vapors in the oral cavity increased with the number of fillings. The concentration of mercury in the oral cavity depends largely on the number of silver amalgam fillings and less so on these fillings' length of service.

Adult↗
PubMed1997

[Enhancing the biocompatibility of dentures made from polymethylmethacrylate by using hydroxyapatite].

Twenty or 50 weight-percent of hydroxyapatite (Polystome) was added in suspensions of AKR-15 copolymer and acid monomers, then the mixtures were molded and subjected to thermal treatment. Admixtures (supercritical CO2) were extracted from the composites in parallel with infrared spectroscopic measurement of the concentration of methylmetacrylate toxic monomers. Hydroxyapatite in 20% concentration decreased the release of toxic substances from the composite, whereas 50% concentration of the agent did not produce this effect. Three patients with intolerance of acrylic plastic were effectively treated using this method.

Biocompatible Materials↗
PubMed1996

[An experimental trial of a hydroxyapatite-based root paste].

Hydroxyapatite-based radicular paste was tried in 12 dogs with experimental chronic periodontitis. Hydroxyapatite, zinc-eugenol, and resorcin-formal pastes were compared. The periodontal status was assessed by morphometric methods. Hydroxyapatite-based radicular paste was found to be the most effective means of treating experimental chronic periodontitis. In control groups the therapeutic effect was either null or minimal.

Animals↗