摘要:

Hietanen, J. Acantholytic cells in pemphigus. A scanning and transmission electron microscopic study.Acta Odontol. Scand. 1982, 40, 257–273Scanning electron microscopy (SEM) was performed on oral scrapings from seven patients with pemphigus vulgaris and one with pemphigus vegetans as well as on skin samples from one of (hose with pemphigus vulgaris. The unstained, fixed, critical-point dried cells were identified with the aid of a light microscope. On the basis of the surface apperance, three main types of acantholytic cells were identified: smooth-surfaced, wrinkled, and microvillous. The acantholytic cells were rounded to ovoid and some showed either a central bulging or a concavity. Small, rounded to ovoid holes or indentations (diameter 0.1–0.3μm) were observed on most cell surfaces. The surfaces of acantholytic cells were occasionally occupied by a few micro-organisms. Neutrophilic polymorphonuclear leuco-cyte/acantholytic cell rosettes were studied by SEM. No gap between acantholytic cell and surrounding leucocytes could be demonstrated. It is postulated that neutrophils may mediate the cytolysis of antibody-coated acantholytic cells. Oral scrapings from one patient with pemphigus vulgaris were collected for transmission electron microscopy (TEM). The acantholytic cells were rounded or ovoid and usually had centrally placed nuclei. Tonofilaments were either randomly distributed or concentrically arranged around the nucleus. In other acantholytic cells there was a halo containing vesicles of varying size around the nucleus. TEM findings suggest that acantholytic cells represent dead or dying cells. Both TEM and SEM findings suggest that when acantholytic cells first separate they may show variable numbers of microvilli, which are probably lost in older acantholytic cells.

ISSN:0001-6357    

DOI:10.3109/00016358209024069

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

A study was conducted to sctutinize the precision of a method for in vivo potential and polarization measurements. The variation with time of the magnitude of currents created at contacts between metallic dental restorations of varying age was also studied.The precision found indicates that the method allows for comparatively precise measurements of potentials to be taken. Studies of performed measurements of polarizations show that the precision of these measurements varies somewhat with contact conditions and the areas of restorations examined.The precision of the currents calculated was found sufficient for precise enough calculation to be made of the magnitude of currents created in the oral cavity.The study also shows a decrease with time of the magnitude of currents created at contacts between metallic dental restorations of varying age.

ISSN:0001-6357    

DOI:10.3109/00016358209024070

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

Unfixed as well as glutaraldehyde-fixed pelleted cells from pure cultures ofStreptococcus mutans subspecies sobrinus(B13) were embedded in glycolme-thacrylate. Uitrathin were sections immunoperoxidase labelled with rabbit anti-S.mutans sobrinusγ-globulin. It was found that unfixed specimens became labelled as precisely and as distinctly as did the fixed specimens. All controls were negative.

ISSN:0001-6357    

DOI:10.3109/00016358209024071

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

The masticatory efficiency was studied among 19 complete denture wearers with their old and new dentures. The test chewing material was gelatin hardened by formalin. A standardized preparation of the test chewing material and the sieve-system is described. The patients were tested on seven different occasions from the period with the old dentures until about 1.5 years after the insertion of the new dentures. The test pieces were chewed for ten seconds - a practice test - 20 seconds and until ready to be swallowed. The chewed material was strained in a sieve-system and masticatory efficiency indices were calculated. The results revealed no statistical significant differences in masticatory efficiency between any of the seven testing occasions with the method used. Thus no significant difference was noticed when patients changed from old to new dentures or during the first 18 months after insertion of new dentures.

ISSN:0001-6357    

DOI:10.3109/00016358209024072

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

While the sugar content of various medicaments has been accepted as a hazard to dental health, the possible detrimental effect of the medicaments per se has been largely overlooked. In the present study the microhardness of dental enamel was examined before and after the exposure to various salts of penicillin, to tetracycline chloride, and to human saliva. The Vickers hardness index was found to1. remain stable or increase slightly in enamel exposed to saliva, non-aqueous penicillin suspensions and certain watery solutions of phenoxy-methylpenicillin calcium2. decrease to a moderate degree in most aqueous penicillin solutions, and3. decrease drastically in tetracycline solutions and in phenoxymethylpenicil-lin calcium solutions containing citrate.The results indicate that a direct reaction may take place between the dental enamel and the medicament and/or its degradation products when antibiotic compounds are takenper os.

ISSN:0001-6357    

DOI:10.3109/00016358209024073

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

The plaque and gingival condition in 232 Swedish schoolchildren aged 13–14 years has been related to the following predictors: plaque, toothbrushing frequency and technique, bristle stiffness of the toothbrush, smoking habits, use of snuff, social class and sex. Multiple regression analyses have been performed in order to explain the variation of plaque index and of gingival index employing these predictors. Significant predictors of plaque index were toothbrushing frequency, sex (boys), number of cigarettes and social class. The predictors which significantly aggravated gingival inflammation were: plaque, use of snuff and the toothbrushing method modified Bass The slight gingival inflammation due to toothbrushing with the modified Bass’method was not due to inferior plaque removal.

ISSN:0001-6357    

DOI:10.3109/00016358209024074

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

Flexural strength of joined and intact specimens of five different alloys were measured. The same alloys were also tested in compression. Joined specimens were also tested in compression. Joined specimens were made by condensing fresh amalgam against the ground surface of 1 week old amalgams.Joined specimens had a flexural strength between 11.5% and 51.4% compared to the intact specimens. The high copper alloys obtained the lowest values for fracture toughness and plastic strain when tested in compression. A positive correlation was shown between flexural strength of joined specimens and plastic strain and between flexural strength of intact specimens and fracture toughness.

ISSN:0001-6357    

DOI:10.3109/00016358209024075

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

Creep characteristics of four light activated composites of different composition were determined at 37 and 50°C. The creep properties were compared with the composition of the materials. The microfill material had higher creep values than those with conventional inorganic particles; possibly due to the inhomogenous distribution of the agglomerated inorganic microfill particles. Furthermore, the fraction of inorganic particles was less than in the conventional composite materials. One conventional composite, however, had nearly the same creep values as the microfill material. The content of a large monomer molecule and poor conversion in this conventional composite material may have contributed to a plasticizing effect. The composite material with the lowest creep values had an oligomer/monomer system leading to short branches with pendant methacrylate groups after polymerization and relatively good conversion.

ISSN:0001-6357    

DOI:10.3109/00016358209024076

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

90 combined gold-amalgam specimens of three dental gold alloys and two amalgams were placed subcutaneously, intraperitoneally and in the cheek pouches of 15 golden hamsters. The appearance of the amalgam surfaces after one week was evaluated using scanning electron microscopy and light microscopy. The results showed that among the implants there was an obvious difference between the conventional amalgam and the non-y2amalgam specimens as regards accumulation of plaque, which was much more pronounced on the conventional amalgams. The cheek pouch specimens with conventional amalgams differed markedly from the corresponding implant specimens, showing very little plaque accumulation. Some possible explanations for these observations arc discussed.

ISSN:0001-6357    

DOI:10.3109/00016358209024077

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

Some porcelain denture teeth and porcelain powders marketed in Sweden have been analyzed for the content of uranium. The fission track method and the delayed neutron technique were the methods used.Compared to results published previously the content of uranium was generally found to be lower in the brands analyzed. The denture teeth contained 23–186 ppm for Anatoform. 35–137 ppm for Myerson. 15—15 ppm for Candu-lor G and 20–53 ppm for Vivopearl. The baked and fired porcelain powders showed values of about 2.8 ppm at most, those in the form of powder about 25 ppm at most.The radiation dose to the mucosa of the upper lip was calculated and is discussed.

ISSN:0001-6357    

DOI:10.3109/00016358209024078

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor