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PubMedDate not supplied

[The interrelation of indices of the functional activity of phagocytosing cells with the status of their receptor apparatus in patients with acute inflammatory diseases of the maxillofacial area].

Rapid techniques were applied to study functional activity of peripheral blood phagocytes in acute sick patients and upon discharge. E-rosette formation is recommended as such rapid technique, for it revealed the cells' superficial E-receptors. The nitro blue tetrazolium reduction test proved useful to probe the oxygen related bactericide mechanisms.

Acute Disease↗
PubMed1983

Three-dimensional measurements of the occlusal surface of upper first molars in a modern Japanese population.

Moiré photographs of the occlusal surface of first molars of Japanese children were taken by means of a specially designed moiré contourograph apparatus. They were then used for three-dimensional measurements. The heights of 4 cusps and some other points were measured by counting contour lines. Distances and angles between them were also measured. Sex differences of these measurements are found mainly around the metacone and hypocone. There is no clear correlation of the four cuspidal heights to the distances between them.

Dental Occlusion↗
PubMed1999

Measurement of changes in dimensions of resorbing alveolar bone: description of a method.

This study evaluated a cast-measuring device used to investigate effects of augmenting fresh extraction sockets with dense hydroxyapatite granules. Following reproducible location of the casts, alterations in ridge tracings were related to radiographically determined ridge height alterations. A randomised controlled study compared two groups of immediate complete denture wearers. One group received conventional immediate dentures, the other received immediate complete dentures after dense hydroxyapatite implantation into canine sockets. Ridge height alterations with time were recorded from radiographs. Alterations in ridge form were recorded from several models transferred reproducibly to a mounting jig attached to a profiling apparatus. Further, the osteo-retentive ability of the hydroxyapatite in the sockets was seen to be close to significance (after six months width differences, in the canine region: P = 0.059, LHS, and P = 0.065, RHS).

Aged↗
PubMedDate not supplied

[A review of the medical equipment displayed at the "Health care-2003" exhibition].

Medical equipment displayed at the "Healthcare-2003" exhibition, that was most representative in the recent years, is surveyed in the paper including the most novel medical devices and apparatuses as well as X-Ray, radiological, intensive-care and neonatal equipment. Besides, outfit for diagnostics, ophthalmology and dentistry, laboratory medical equipment, medical instruments, technological medical equipment and portable medical devices were demonstrated at the exhibition. Therefore, considering the diversity of medical equipment displayed, any medical facility in Russia would be able to choose the devices it needs.

Chemistry, Clinical↗
PubMed1990

Characterization of two small-particle composite resins.

The in vitro occlusal wear of two recently introduced, small-particle composite resins was evaluated. Twelve disks of each material were opposed by maxillary third molars and subjected to 300,000 masticatory cycles in a servohydraulic model of the human masticatory apparatus. Before and after profiles of the surfaces of both the disks and the teeth were mapped and digitally recorded on magnetic disks. P-50 disks showed significantly (P less than .05) less volume loss than did Herculite disks. Enamel that opposed P-50 disks showed significantly (P less than .001) more wear than did enamel that opposed Herculite disks.

Composite Resins↗
PubMed1996

Gene expression of TGF-beta 1 and elaboration of extracellular matrix using in situ hybridization and EM radioautography during dentinogenesis.

BACKGROUND AND METHODS: The expressions of TGF-beta 1 and Type I collagen mRNA were studied by in situ hybridization and immunohistochemistry then the secretory pathway of dentin phosphoprotein was investigated electron microscopic radioautography in rat incisors. RESULTS AND CONCLUSIONS: Expression of TGF-beta 1 mRNA was observed in dental papilla cells before dentin formation. The signals were most intense in pre- and postodontoblasts and during dentinogenesis, but became weaker in the secretory region during the dentin formation. Type I collagen mRNA was expressed in essentially the same as that of TGF-beta 1. These results suggest that TGF-beta 1 plays an important role in the differentiation of, and collagen synthesis by odontoblasts. Radioautography showed radioactivity in the rough endoplasmic reticulum 5 min after injection of 3H-serine. Silver grains were observed over the cylindrical portions of the cis-face of the Golgi apparatus at 10 min and over the cylindrical portions of the transface at 20 min. The secretory granules showed the strongest reaction between 20 min and 1 h after injection. At 45 min, a significant labeled band appeared at the mineralization front. The pathway of 3H-proline was essentially the same as that of 3H-serine, but 3H-proline moved more slowly. Secretory granules were heavily labeled from 30 min; no labeling was found at the mineralization front at 45 min. The labeling pattern with 3H-serine appears to be closely related to the localization of phosphoproteins. Dentin phosphoproteins are related to secretory granules and are secreted by odontoblasts as the mineralization front, being involved in the process of dentin mineralization.

Animals↗
PubMed1990

Relationships between tooth eruption, occlusion and alveolar bone resorption: cytological and cytochemical studies of bone resorption on rat incisor alveolar bone facing the enamel.

The rat labial incisor alveolar bone facing the enamel and bearing the occlusal force was examined by electron microscopy after being compared with the lingual alveolar bone by histological and scanning electron microscopic (SEM) observations. On the labial side, shallow resorptive lacunae were recognized all over the bone surface; these were mainly covered by osteoclasts and some mononuclear cells. The cement line was absent from the bone matrix. On the lingual side, residues of Sharpey's fibers, the bone formation surface and deep resorptive lacunae were observed by SEM. Histologically, bone remodeling areas showing both osteoclasts and active bone-forming osteoblasts on the bone surface, as well as many cement lines in bone matrix, were recognized. Furthermore, electron microscopic and cytochemical studies demonstrated that mononuclear cells located close to osteoclasts displayed osteoblastic characteristics such as alkaline phosphatase activity, a developed Golgi apparatus, and a rough endoplasmic reticulum. These findings indicate that continuous bone resorption occurs on the labial bone surface, while active bone remodeling occurs on the lingual surface. Even on the labial surface, osteoblastic cells close to osteoclasts seem to play an important role in the differentiation and or activation of osteoclasts.

Acid Phosphatase↗
PubMedDate not supplied

[Experimental study of accuracy of electro-odontometric device in establishment of apical constriction of a root canal].

The aim of the present study was to investigate the accuracy of an electro-odontometric device "Odontometer" (Goof, Denmark) in the determination of the exact location of the apical constriction in root canals of extracted teeth in experimental conditions. Ninetynine root canals of 91 teeth were used. Following the access to the root canal the teeth were sealed at the level of the cemento-enamel junction in the apertures of a plastic plate. Each plate contained ten tooth samples. The plate was immersed into a gelatine medium. The roots were completely immersed but the crowns were isolated from the medium by the plastic plate and sticky wax seal, remaining at the top surface of the plate. The platinum plate was immersed in the gelatine medium and connected to the passive electrode of the device. The active electrode was a K-reamer n. 15 which was advanced along the canal until "Odontometer" indicated "apical constriction". At this point the reamer was sealed in the canal, and the toot was released from the apparatus. The apical third of the root was then ground parallel to the long axis until the distal segment of the K-reamer and the root canal appeared. The distance between the tip of the reamer and the apical constriction was measured with a microscope precision of 0.125 mm. The absolutely exact location of the apical constriction was determined in 22% of cases. In no case the endocanal electrode passed over the anatomic foramen. With the tolerance of the clinically acceptable odontometric error of 0.5 mm, "Odontometer" was accurate in 83% of cases thus its use in current dental practice is justified.

Dental Pulp Cavity↗
PubMed1987

Rhabdomyolysis and acute renal failure following use of succinylcholine and enflurane: report of a case.

A case of succinylcholine and enflurane induced rhabdomyolysis and myoglobinuric acute renal failure in a mentally retarded patient is presented. The report illustrates some principles of management and the correlation of laboratory findings with the syndrome. When using general anesthesia in mentally retarded patients it is recommended that: 1) a careful personal and family past anesthetic history be taken; 2) drugs and apparatus for treatment of the crisis be available before anesthesia is induced; 3) the use of succinylcholine and potent inhalation anesthetic agents be avoided; 4) there is early diagnosis by prompt recognition of the clinical signs; and 5) that body temperature monitoring and frequent observation of vital signs during and after an operation be carried out.

Acute Kidney Injury↗
PubMed1977

Bacterial contamination and transmission by nitrous oxide sedation apparatus.

Microbial contamination of sterile nasal hoods was demonstrated in nine of twenty-one clinical administrations of nitrous oxide-oxygen conscious sedation. In each case, bacteria isolated from the hood after 30 minutes' use were correlated morphologically with organisms recovered from the subject's nasal mucosa. A laboratory investigation utilizing an artificial respiration-sedation system revealed that there is a significant possibility of cross-infection between patients when improperly disinfected sedation equipment is employed.

Adult↗
PubMed1997

Accuracy of apex locator.

An evaluation of the accuracy of the "Root ZX" apex locator was conducted on 20 single-rooted teeth that had been extracted because of severe disease or orthodontic treatment. After the pulp chamber had been accessed and the tooth length determined using the Root ZX apparatus, the file was fixed to the tooth with light-cured composite resin. After extraction, the tooth was longitudinally ground with a diamond bur until the file was visible. The distance between the file tip and the apical foramen was measured under a microscope (x 100). The results showed that the tip of the instrument reached the apical foramen in all teeth.

Adult↗
PubMed1985

Periodontal aspects of porcelain restorations.

At present, no man-made restorative can match the biologic acceptance of a hygienic natural tooth surface. Ideally, no restorative material would approach the gingival apparatus. However, as case demands often dictate violating this ideal, careful adherence to the principles discussed will minimize the damage to the periodontium. Ultimately, the response of the periodontal tissue will give the final approval or disapproval of any restorative procedure. The principles discussed must be considered at all phases of any restorative procedure. They must always be of primary concern.

Animals↗
PubMed1984

An application of the moiré method to three-dimensional measurements of the occlusal aspects of molars.

Moiré photographs of the occlusal surface of human molars were made by means of a specially designed apparatus for moiré contourography. Since molars show contour lines with equal intervals, three-dimensional measurement of the complicated relief of the occlusal surface is possible. The positioning of molar teeth for making the photographs and the technique of the moiré photography for small objects were presented. The three-dimensional measuring method of the molar surface and its use for anthropological purpose were discussed.

Dental Occlusion↗
PubMed1997

Polymerization contraction stress in thin resin composite layers as a function of layer thickness.

OBJECTIVES: In the present study, the effect of layer thickness on the curing stress in thin resin composite layers was investigated. Since the value of the contraction stress is dependent on the compliance of the measuring equipment (especially for thin films), a method to determine the compliance of the test apparatus was tested. METHODS: A chemically initiated resin composite (Clearfil F2, Kuraray) was inserted between two sandblasted and silane-coated stainless steel discs in a tensilometer. The curing contraction of the cylindrical samples was continuously counteracted by feedback displacement of the tensilometer crosshead, and the curing stress development was registered. After 20 min, the samples were loaded in tension until fracture. The curing stress was determined for layer thicknesses of 50, 100, 200, 300, 400, 500, 600, 700 microns, 1.4 mm and 2.7 mm. The compliance of the apparatus was calculated with the aid of a non-linear regression analysis, using an equation derived from Hooke's Law as the model. RESULTS: None of the samples fractured due to contraction stress prior to tensile loading. The contraction stress after 20 min decreased from 23.3 +/- 5.3 MPa for the 50 microns layer to 5.5 +/- 0.6 MPa for the 2.7 mm layer. The compliance on the apparatus was 0.029 mm/MPa. SIGNIFICANCE: A measuring method was developed which was found to be suitable for the determination of axial polymerization contraction stress in this films of chemically initiated resin composites. The method makes it possible to estimate the stress levels that occur in resin composite films in the clinical situation.

Analysis of Variance↗
PubMed2001

Adhesion of a glass-ionomer root canal sealer to the root canal wall.

Glass-ionomer root canal sealer is commonly used because of its chemical bonding and favorable physical characteristics when bonding to dentin. This study was designed to determine the tensile bond strength of a glass-ionomer sealer (Ketac Endo, Espe, Seefeld, Germany) on root canal walls after pretreatment with different conditioners. Flat inner surfaces of root canal specimens were prepared. The specimens were divided into five groups of 10 teeth, and the groups were conditioned with one of the following smear layer removal solutions: 15% EDTA/NaOCl, 10% polyacrylic acid, 35% phosphoric acid, 6% citric acid, and 5.25% NaOCl as a control. Then the exposed root canal areas were coated with Ketac-Endo. Tensile bonding was measured using a universal testing machine until ultimate failure was obtained. The groups that were treated with phosphoric acid and citric acid showed significantly higher bond strengths than the groups that were treated with 15% EDTA and polyacrylic acid (p < 0.05). Bonding to dentin without smear layer removal (NaOCl group) was too low to be measured in the testing apparatus. Scanning electron microscopy confirmed that phosphoric and citric acids were more effective in removing smear layer than EDTA or polyacrylic acid. The result supported the view that pretreatment with phosphoric acid or citric acid should be used in association with glass-ionomer root canal sealer to achieve the most effective removal of the smear layer and to provide better adhesion.

Acid Etching, Dental↗
PubMed1989

[Fundamental investigation of impulse of response to experimental full crowns on variation of abutment forms].

The purpose of this study was to represent the amount of the vibration as a response in experimental full crowns that occurs at a shock impulse and to offer the relation between the response and abutment forms. Several authors have reported the use of shock forces as a method of prosthetic vibration researching, but in those cases the importance is to require how to gain the REAL SHOCK. The author used two types of shock apparatus and obtained the optimal shock force in the experimental crown vibrations. Shock response increased as input increase, but the response decreased at the maximal point. Optimal shock was obtained at the condition, that is, 195.56 gr.cm/sec. in momentum. Experimental crown response was related to the contact area of the crown and abutment. Decayed abutments decreased the value of the optimal shock force.

Bite Force↗
PubMed1987

Ultrastructural and morphometric analyses of human cementoblasts and periodontal fibroblasts.

In order to elucidate the cytological characteristics of human cementoblasts which distinguish them from periodontal fibroblasts, the periodontal ligament and gingival connective tissue attached to 37 extracted teeth from 27 patients (ages 10-67) were analyzed by electron microscopy coupled with a morphometric procedure. The cementoblasts largely consisted of either immature or resting types of collagen-producing cells (CPC), both of which were poor in the rough endoplasmic reticulum and Golgi complex; these organelles were well-developed in the relatively less common active cementoblasts. The cementoblasts consistently revealed a higher mean-volume-density per tissue unit than the fibroblasts and sometimes were grouped into clusters with the formation of junctional apparatuses. The relative volume of glycogen particles per cytoplasm was significantly higher in the cementoblasts, whereas the rough endoplasmic reticulum was higher in the fibroblasts. From the present study, it is suggested that the cementoblasts are functionally less active CPC than the periodontal fibroblasts.

Actin Cytoskeleton↗
PubMed1989

[Computer-supported analysis of occlusion using T-Scan system. First report].

We got first experiences with a computer-aided apparatus for occlusion-analysis. This apparatus is able to measure times of beginning and pressure of each occlusion-contact by a special foil. There is also the possibility to record functional movements on a film. Each measure result appearing on the screen, can be documented by an installed printer. The T-Scan-System can either be used for diagnosis or for medical attention in all domains of occlusion and articulation.

Dental Occlusion↗