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Biomedical subjects

A S Grigor'ian

Publications and source records attributed to A S Grigor'ian.

At least 19 recordsLinked to original sources
PubMed2006

[Experimental-morphological study of the effects of diode laser scalpel with different irradiation parameters (wave length 0.97 mm) on oral mucosa].

An experimental-morphologic study of the effects of diode laser scalpel with different irradiation parameters (wave length 0.97 mm) on oral mucosa of 12 rabbits showed that incisions on oral membrane of the tongue, cheek and palate made by diode laser scalpel in different modes of operation (diode laser scalpel LC-0.97-IRE-Polus: in continuous mode /4 W/; frequency modulated mode 2000 x 100 /5 W/; frequency modulated mode 1000 x 50 /6 W/) after 2 hours produced the effect of superficial tissues defects with consequent development in 1-2 days of necrotic changes, oedema and angiomatosis, as well as perifocal inflammatory and productive reactions in the defects walls. In the continuous mode /4 W/ and frequency modulated mode 2000 x 100 /5 W/ to 10th day of the experiment there was epithelization of mucous defects on thr tongue, cheek and palate. This effect was observed only on day 20 after the frequency modulated mode 1000 x 50 /6 W/. In the control (incisions by radio-wave scalpel) epithelization of oral mucous membrane defects was seen on day 5-10 that was comparable with laser scalpel effects. Thus optimal results (by criterion of oral mucous membrane incisions healing) were received in the continuous mode /4 W/ and frequency modulated mode 2000 x 100 /5 W/.

Animals↗
PubMed2006

[Morpho-functional fundamentals of inflammatory periodontal disease clinical symptomatology].

On the basis of their own observations and literature data analysis of most frequently occurring clinical symptoms in cases of inflammatory periodontal disease is given and their pathogenetic fundamentals are disclosed. Special attention is paid to mechanisms of chronic inflammatory process symptoms formation in periodontal tissues, attempt is made to find a distinction between clinical manifestations of different forms of chronic inflammatory process, gingivitis and periodontal relying on conception of morpho-functional fundamentals of the disease clinical symptomatology. Clinical symptoms of inflammatory diseases are considered as sublimation of their pathogenetic fundamentals and as clinical manifestations of the basic for pathology processes of tissue structure injuries and functional disturbances.

Chronic Disease↗
PubMed2005

[Efficacy of use of X-ray contrast carbon material in maxillo-facial surgery].

The possibilities of the use of carbon implants in cases of any defects of any part of facial skeleton and soft tissues of both inherent and acquired nature were studied. Taking into account X-ray transparency of carbon implants the experiment was carried out to make the material X-ray contrast when using the addition of powdered metallic boron in the range of concentrations 8-12%. It was successful and the samples were visualized. In these cases spiral computed tomography is the optimal tool to make all deformation volume clear, to plan operative interventions and to observe the treatment results.

Adult↗
PubMed2002

[Morphogenesis of early stages of periodontal inflammations].

Morphological signs of dissemination of active inflammatory process beyond the gingiva into the depth of the alveolar process bone tissue, paralleled by numerous destructive changes (bone resorption and lysis of collagen fibers of the periodontal ligament, plunged into the bone) in the periodontium are observed during clinically manifest chronic gingivitis. Hence, in contrast to the concept universally acknowledged in periodontology, despite the seeming clinical "heterogeneity" of gingivitis and periodontitis, these conditions should be regarded as a periodontal inflammation, because, judging by the detected morphological picture, each of the nosological entities acknowledged today (chronic gingivitis, periodontitis) represents just a successive stage of the same chronic inflammatory process differing only quantitatively but not qualitatively.

Alveolar Bone Loss↗
PubMed2002

[Acoustic microscopy methods in studies of the filling materials microstructure].

The structure of filling materials (kemfil, polyacrylate cement, and Dentis, material produced by Stomadent Firm in Russia) at the interface with human dentin was studied in teeth subjected to retrograde filling with preliminary appendectomy. A prototype of table wide-field short pulse scanning acoustic microscope (50 mHz) (Acoustic Microscopy Center, Institute of Biochemical Physics of Russian Academy of Sciences) and Elsam acoustic microscope (200 mHz) (Leitz, Germany) were used. The results indicate that analysis of acoustic characteristics, including the data of acoustic microscopy, helps investigate the cement microstructure and evaluate the compactness and elasticity of samples; moreover, structural elements of the material, which are undetectable by other methods, are seen on acoustic images. These data can be used for evaluating the relationship between the microstructure and formation of mechanical properties, and, maybe, the patterns of cement interactions with dental tissues.

Acoustics↗
PubMed2002

[Study of protective effect of perftoran on a skin flaps].

Differences in the levels of tissue respiration in the rat skin flaps incubated in perfluothane (PF) and normal saline (NS) are regarded as an evidence of local PF effect on tissue substrate. The complex of metabolic changes in the skin fragments under the effect of PF in comparison with skin fragments incubated in NS indicate a protective effect of PF on tissue substrata. Decreased content of malonic dialdehyde and a slower accumulation of tissue liquid in skin flaps incubated in PF, in comparison with the fragments incubated in NS, is worthy of note. It indicates that incubation in PF (in comparison with incubation in NS) is less harmful for cell membranes and induces lesser disorders in water-salt metabolism and edema which are usually associated with tissue lesions developing under conditions of trophic deficiency.

Animals↗
PubMed2002

[Optimization of structural characteristics of a root canal wall during retrograde tooth filling on a basis of scanning electron microscopy data].

Studies by scanning electron microscopy showed that dentin of the root stump (resection of the root apex is an obligatory condition of retrograde filling) has numerous regular dentin tubules, in contrast to the apical part of the root. Mechanical treatment of dentin during preparation of the platform for retrograde filling leads to the formation of a thick "lubricating" layer on the surface of these platform. This layer consists of corpuscles of destroyed tissue substance (smudge) and completely covers the ends of dentin tubules, thus preventing the formation of strong bonds between the filling material and dentin surface. Treatment (pickling) of the platform surface with the conditioner notably improved the adhesion of Russian filling material Dentis to dentin. The best adhesive effect of retrograde filling was attained with Kemfil, the material requiring no pickling pretreatment.

Adhesiveness↗
PubMed2002

[Efficiency of M-22 human fibroblast culture as a tissue engineering factor in plastic repair of mandibular bone defects].

The results of inoculation of human fibroblast (strain M-22) and rabbit fibroblast cultures in standard bone defects were studied in 4 groups of rabbits 3 days to 3 months after inoculation of the cultures together with osteoplastic material (collapol KP-2). In the control groups the defects healed under a blood clot (group 1) or were filled with KP-2 (group 2). Histomorphological analysis of tissue showed that inoculation of M-22 cell culture into bone defects notably activated reparative osteogenesis in osseous wounds and stimulated healing, which was more rapid than in other groups. Inoculation of rabbit fibroblast culture in bone defects slightly inhibited the healing of bone wounds.

Animals↗
PubMed2002

[Preparation of hard dental tissues by aeroabrasive method].

The efficiency of aeroabrasive preparation (AAP) of teeth was evaluated by clinical methods and scanning electron microscopy. The authors conclude that the use of AAP should be confined to the treatment of surface and medium caries. Analgesia before AAP is obligatory, except cases with preparation of fissures for preventive hermetization. The use of AAP is absolutely contraindicated in cases of allergic reactions in the patient, dentist, or assistant. Methods for protection of the dentist, assistant, and patient during the use of AAP are discussed.

Adult↗
PubMed2001

[Key components of pathogenesis of periodontal diseases in light of cytomorphological findings].

A new cytomorphometrical method for evaluation of periodontal status by cytograms of gingival impressions is based on estimation of destruction index and inflammatory destructive index. This method will be helpful in the diagnosis of periodontal diseases, monitoring of the pathological process after treatment, and in solution of theoretical problems, e.g. investigation of the key factors in the pathogenesis of periodontal diseases. The authors analyze the relationship between the two major components of pathogenesis of periodontal inflammation-inflammatory infiltrative process and destructive changes.

Humans↗
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

[Use of a new biological factor--exogenous nitric oxide--during surgical treatment of periodontitis].

In order to improve the efficiency of surgical treatment of periodontitis, the operative wound was exposed to nitrogen oxide (NO) during osteogingivoplasty and on days 3, 5, and 6 after it. Clinical and laboratory data making use of the cytomorphometrical method indicate that NO exposure decreased and maybe prevented secondary injury to the operation wound in up to 46.6% patients, which was confirmed by decrease and even normalization of destruction index and inflammatory destructive index on days 7 and 14, which was not observed in the reference group patients not exposed to NO.

Case-Control Studies↗
PubMed2001

[A comparative analysis of healing mandibular defects due to exposure to different plastic materials (experimental morphological study)].

Autogenous bone grafts are the most effective factor able to activate osteogenesis in bone defects, as shown by our experiments. Experimental biomaterials such as Bio-Oss and KP-3 have a high osteogenesis potential, too. However the callus initiated in jaw defects by those biomaterials underwent partial reduction during secondary rebuilding, thus becoming a less authentic bone formation.

Animals↗
PubMed2000

[The pathogenesis of posttraumatic deformities of the mandible in the growing organism].

Experiments on developing animals showed that mandibular fractures of any location can be complicated by pronounced growth disorders and abnormal development of mandibular bone, leading to deformations of the site of fracture. Abnormal mandibular development was particularly obvious after injuries to the condyle and condylar process, after fractures of mandibular body and angle with dissection of the neurovascular bundle, and in cases with osteomyelitis. Disorders in endochondral bone formation (which is normally most active in the condyle) caused by traumatic processes and disorders in neurotrophic regulation and blood supply to the bone, developing in neurovascular obstruction, underlie the mechanisms of posttraumatic mandibular deformations. These complications were observed in patients with fractures of different sites because of improper joining and fixation of fragments. Children should be regularly checked up after mandibular fractures. Measures aimed at prevention of growth disorders and development of mandibular bone lesions are obligatory at all stages of examination.

Adolescent↗
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

[A comparative analysis of the efficacy of different types of filling materials in the surgical elimination of tooth perforations (experimental morphological research)].

Based on the experimental morphological findings, the authors compare the efficiency of tooth perforation repair in experimental animals by surgical method using Dyract compomer, Base Line glass ionomeric cement, and Ostim-100 osteoplastic material. The data indicate a high efficiency of this method. Base Line material is preferable for filling the perforation in dental wall, as it reliably performed the isolating function under experimental conditions.

Animals↗