[Harmonic imaging analysis for assessment of morphological changes in mini-pig alveolar bone by normal and increased functional load].

The aim of the study was to reveal the mastication forces effect on the microstructure of mandible bone tissue of mini-pigs by Fouirier harmonic imaging analysis of bone sections images of back scattered electrons and assessment of calcium and phosphorous distribution maps obtained by roentgenofluorescence technique. The results showed that by higher functional loads not only the total content of mineral elements in the bone matrix increased but also the of the low-frequency harmonics in the image spectrum indicating structural heterogeneity decrease in bone mineralization.

[Use of Fourier analysis in hystomorphometry].

The mandible alveolar bone tissue of mini-pig was evaluated by means of radiospectral analysis. Fourier analysis of mineral content distribution in bone slices showed that loss of masticatory load leads to focal demineralization. With time the demineralization foci increased in amount, not in size.

[Lab study of splinted teeth mobility with the help of periotestmetry].

Mobility of splinted teeth was determined with the help of the device Periotest, its meterage depended upon abutment fixation nature and their number. Critical for the device sensitivity was the weight of splinting construction equal to 12.71+/-0.81 g.

[Masticatory loading influence upon dental pulp functional status and its blood supply].

By pheodentography and Doppler laser flowmetry in 53 volunteers with clinically healthy parodontal tissues or parodontitis of light degree the masticatory teeth dental pulp functional status and its blood supply including microcirculation was studied. It was established that in case of one-sided type of chewing masticatory loading reduction on nonworking side increased vessel's tonus and capillary blood flow level. In case of regular use of chewing gum and filbert nuts vasoconstriction was developed, blood supply was considerably reduced and capillary blood flow level in the pulp was sharply increased that made up its functional adaptive mechanism of defense for the provision of plastic odontoblast function.

[Chewing gum influence upon blood supply of mastication muscles].

A total of 27 volunteers 16-26 years of age participated in the study of the influence of chewing gum use in different regimens upon velocity parameters of blood supply of mastication muscles at dopplerography (MM-D-K dopplerograph made in Russia). It was established that regular and continuous (30 min) chewing the gum and also of big volume (in two) but short-term chewing (5 min) equalizes blood supply of mastication muscles on both working and non-working sides.

[Influence of course use of chewing gum on alveolar bone density].

Efficacy of course use of chewing gum for alveolar bone reinforcement was studied with the use of digital X-ray-graphy at three levels of interalveolar bone in 93 patients with clinically different periodontal tissue conditions. It was established that optical density of alveolar bone is higher on the working side than on the inactive side and it depended upon clinical status of periodontal tissues. Top of the interalveolar bone had the lowest density, the middle part - the highest. Course use of chewing gum in the optimal regimen increased interalveolar bone optical density, at that to a greater extent on the inactive side and in the upper part of it.

[Changes of functional-diagnostic indices during occlusive contacts reestablishment in the process of orthodontic treatment of patients with incisal disocclusion].

During orthodontic treatment of 42 patients with incisal disocclusions of different severity stages it was determined that during the period of occlusal contacts reestablishment a considerable increase of regional blood flow, a decrease of jaw bone density and an increase of masticatory muscles functional activity occurred. These changes were more pronounced in cases of deep incisal disocclusion than in cases with other types of incisal disocclusion.

[Hemodynamics in the pulp of abutment teeth after their preparation for metal-ceramic denture restoration at various degree of lateral wall convergence]. / Gemodinamika v pul'pe zubov, preparirovannykh dlia izgotovleniia metallokeramicheskikh protezov pri razlichnoi stepeni konvergenstii bokovykh stenok.

Reaction of the pulp to degree-by-degree changes (from 3 to 18 degrees) in inclination of lateral walls of abutment teeth during preparation for cermet dentures was studied by the functional diagnosis methods (electroodontodiagnosis, rheodentography) in 50 patients with intact abutment teeth. Changes in dental pulp electric conductivity and hemodynamics depended on the inclination angle formed during preparation. The optimal safe angle of the lateral wall inclination was determined to be 3-12 degrees. Increase of the angle (> 12 degrees) can lead to traumatic pulpitis.

[Effect of masticatory load on oxygen tension in periodontal tissues]. / Vliianie zhevatel'nykh nagruzok na napriazhenie kisloroda v tkaniiakh parodonta.

Relationship between the effect of occlusional loading (weak, 10-15 H, and strong, 120-150 H) and oxygen tension (pO2) in periodontal tissues adjacent to the first molar on the working and resting sides was carried out in 57 subjects with different clinical status of the periodontium and with partial secondary adentia. pO2 decreased during exercise, the most pronounced drop (to 12 mm Hg) being observed during intensive exercise. The level of pO2 decreased greater on the resting side and in patients with periodontal diseases. The longest period of pO2 recovery (up to 50 min) was observed after intensive exercise.

[Hemodynamic changes in the periodontium with the use of chewing gum]. / Issledovanie izmenenii gemodinamiki parodonta pri ispol'zovanii zhevatel'noi rezinki.

The effect of gum chewing (5 min after meals 3 times a day) on periodontal blood supply was studied in a group of 52 volunteers with different clinical status of the periodontium. Tonic strain in the local vessels changed (fluctuated) little (by 2-7%). Tonic strain was shifted on the inert side and in patients with periodontal diseases. Blood consumption increased by 33%. Regular gum chewing for 10 min resulted in compensatory vasoconstriction and hyperemia of the periodontium starting from the second week, irrespective of the initial clinical status of the periodontium.

[A comprehensive study of the mechanical effects of the long-term and regular use of chewing gum]. / Kompleksnoe izuchenie mekhanicheskogo vodeistviia dlitel'nogo i reguliarnogo ispol'zovaniia zhevatel'noi rezinki.

The results of regular gum chewing (30 min 3 times a day after meals for 4 weeks) were assessed in 46 volunteers by the functional diagnosis methods. Chronometry of food chewing and arbitrary gum chewing for 30 min was carried out before the investigation. Daily duration of food chewing is about 33 min. During gum chewing, the number of masticatory strikes on the inert side is higher during the first 5 min and then levels. This leads to levelling of mechanical loading of the lateral parts of the jaws and of bioelectrical activity in the masticatory muscles proper. The gum is bit 3-5 times more often with frontal teeth than with lateral teeth. Regular use of chewing gum notably increases the blood supply to the periodontium, and the regulatory mechanisms fail to cope with it in periodontal diseases; this leads to venous congestion in the regional vascular system.

[The mechanical action of Dirol chewing gum on the periodontal tissues and masticatory muscles]. / Mekhanicheskoe vozdeistvie zhevatel'noi rezinki Dirol na tkani parodonta i zhevatel'nye myshtsy.

Regional hemodynamics, bioelectric activity of masticatory muscles, and compactness of mandibular bone were studied by the rheographic method for measuring periodontal bloodflow, by electromyography, and echo-osteometry in 52 volunteers after 4-week regular chewing of Dirol chewing gum. Congestive hyperemia develops in periodontal tissues; functional activity of masticatory muscles and compactness of mandibular bone are normal.

[The microcirculation in periodontal tissues: 2. The action of the regular use of chewing gum]. / Mikrotsirkuliatsiia v tkaniakh parodonta: 2. Deistvie reguliarnogo ispol'zovaniia zhevatel'noi rezinki.

The effect of regular use of chewing gum (for 28 days) on microcirculation was assessed in 35 patients with slight and medium-severe periodontitis by biomicroscopy and laser Doppler flowmetry. Microcirculation normalized immediately after chewing training due to arrest of arteriolar spasm. In slight periodontitis the effect persists for almost one year, in medium-severe condition for up to 6 months, because of more expressed structural changes in the microvessels of periodontal tissue.

[The microcirculation in the periodontal tissues: I. The dynamics of functional hyperemia]. / Mikrotsirkuliatsiia v tkaniakh parodonta: I. Dinamika funktsional'noi giperemii.

Study of functional hyperemia of the gingival microcirculatory network by biomicroscopy and laser Doppler flowmetry showed that in normal periodontium, the microcirculation index increased by 70% immediately after mechanical loading created by the gnathodynamometer, whereas in slight or medium-severe periodontitis it increased only by the and of the first minute, the peak bloodflow values being 31 and 19%, respectively. In grave periodontitis the microcirculation index was 6% decreased immediately after loading and increased only by the fifth minute, which is explained by notable changes in the angioarchitectonics of periodontal microvessels.