Search PubMed⌕ Search

Biomedical subjects

V K Leont'ev

Publications and source records attributed to V K Leont'ev.

At least 19 recordsLinked to original sources
PubMed2005

[Structural properties of mixed saliva in persons with different levels of tooth resistance to caries].

Structural properties of mixed saliva were studied in 30 persons 16-18 years of age divided into 3 groups (10 persons in each) according to different levels of tooth resistance to caries -- 1st with high level of resistance (DMFT=0), 2nd with medium level of resistance (DMFT=4.3+/-0.82), 3rd with low level of resistance (DMFT=6.6+/-0.92). The difference between DMFT figures in groups 2 and 3 was insignificant. In salivary filtrate (collected in the rest conditions and after 5 g sugar load) pH (by potentiometry) and optical density (by photoelectric colorimetry) were determined. 60 saliva samples were collected and 240 determinations were made. In was found that 5 g sugar intake led to structural changes of oral fluid in all groups with different levels of tooth resistance to caries. But in persons with 0 caries incidence the oral fluid micelle resistance and saliva mineralizing capacity were higher than in persons with medium and low resistance to caries. The received data may be used for revelation of oral mineral homeostasis mechanisms and forecasting pathology arising in cases of its disturbance and for planning preventive and curative measures with consideration of their corrections depending upon the level of the individual resistance to caries.

Adolescent↗
PubMed2004

[Optic coherent tomography in evaluation of the buccal mucosa status. Communication 1. Normal mucosa].

The potentialities of optic coherent tomography (OCT) in the diagnosis of the buccal mucosa status were studied and the results are presented in two communications. Communication 1 demonstrates the tomograms of various parts of normal buccal mucosa and methods of their identification as exemplified by analysis of 1180 in vivo and 43 ex vivo OCT images. Using parallel histo-tomographic comparison, the authors distinguished the main signs of optic images, depending on the type of epithelium and characteristic features of the connective tissue stroma in various parts of the buccal mucosa. These signs are essential for understanding the optic images of the mucosa in disease, which will be shown in communication 2.

Adult↗
PubMed2004

[Optical coherence tomography in the evaluation of the oral cavity mucosa. Part II. Benign and malignant diseases].

This paper is the last one in the series of publications on the investigation of the capability of Optical Coherence Tomography (OCT) in diagnostic of state of oral cavity mucosa. Part II demonstrates the diversity of optical images, different forms specific to leukoplakia, lichen planus and squamous cell carcinoma on the basis of the investigation of 56 pathologic lesions of 43 patients with precancer and cancer of oral cavity. The OCT sensitivity in malignancy detection in oral cavity is high - 83%, specificity is 98%, and accuracy is 81%. The kappa coefficient of interobserver agreement is 0.76.

Carcinoma, Squamous Cell↗
PubMed2002

[Stomatological studies on board of an "airspace" station].

The status of the oral organs was evaluated in normal subjects exposed for a long (30-262 days) time to conditions simulating an airspace flight in an on-land experimental complex (Sphinx-99 experiment). Stomatological studies were carried out in 15 volunteers aged 28-48 years. The initial (before "flight") and post-flight examination included clinical examination of the maxillofacial area and oral organs, evaluation of the intensity of caries by the CDL index, evaluation of the periodontal tissue status by the PMA and SPITN indexes. Based on the data, we singled out periods of adaptation characteristic of the oral organs under conditions of long enclosure. The results allow prediction of the course of diseases of the oral organs under extreme conditions and recommend methods of purposeful prevention in certain terms.

Adaptation, Physiological↗
PubMed2002

[Structural characteristics of mixed saliva in patients with caries at different CDL values].

Structural characteristics of mixed salivary pools were studied in 20 subjects aged 16-18 years. The examinees were divided into 2 groups, 10 subjects per group. Group 1 included patients with negligible caries involvement (CDL index 3.0 +/- 0.62), group 2 consisted of patients with greater involvement (CDL index 10.1 +/- 0.62). Statistically significant differences between these groups were detected for 2 parameters: pH and optical density. Acidification of the saliva and its optical density were higher in patients with greater caries involvement. Structural characteristics of the saliva were disordered in patients with multiple caries, which indicated impairment of mechanisms maintaining Ca2+ and HPO4(2-) ions in an oversaturated state and a decrease in the mineralizing potential of oral fluid. These data can be used for explaining the molecular mechanisms of homeostasis disorders in the oral cavity and evaluating the efficiency of preventive and therapeutic measures at early stages of dental caries.

Adolescent↗
PubMed2002

[Caries resistance].

Discussing the problems of caries resistance and caries susceptibility, we should remember that normal status of dental enamel is maintained by the dynamic equilibrium between demineralization and remineralization processes. Some aspects in the structural resistance of the enamel, determined by its maturing, are discussed. Data on the role of oral factors reflecting the status of the organism are presented. The authors do not agree that caries resistance, which is permanent throughout life, is determined by the CDL index. They give their arguments in favor of introducing the notion of "caries risk" and the criteria for evaluating this risk.

Dental Caries↗
PubMed2002

[Dental caries resistance under conditions of a space flight].

The maxillodental status of aeronauts attracts special interest of scientists and causes apprehensions of physicians and scientists of countries with aeronautic industry because of long duration of space missions. Some scientists consider that the realization of mission to Mars can lead to development of multiple dental caries in aeronauts. The aim of this study was to study the effects of space mission factors on the resistance of hard dental tissues and remineralizing activity of the saliva in a simulation experiment. The results demonstrated dynamic changes in the studied parameters under the effect of space mission factors; based on these results, we determined the criteria for selection of candidates for prolonged experiments and space missions.

Dental Caries↗