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Biomedical subjects

E Hals

Publications and source records attributed to E Hals.

At least 37 records · Page 2Linked to original sources
PubMed1980

Selective fluorescence of mast cells: comparison of effect of staining with acid and basic dyes.

A previously described method in which mature rat mast cells stained with acid dyes were demonstrated by their selective fluorescence, was further studied. The material consisted of tongues from rats and mice in addition to heads and tails from 1-d-old rats and embryos 19 d post gestations stage. Chronically inflamed human gingiva obtained from gingivectomies was also studied. Some basic dyes were used for control and comparison. With the acid dyes acid fuchsin, fast green FCF and azocarmine G a mast cell fluorescence equal to that in rats was also demonstrated in mice and humans. Immature rat mast cells stained with acid dyes disclosed a selective fluorescence, the intensity of which was, however, lower than that observed with the basic dye acridine orange. Immature mast cells in the chronically inflamed gingiva revealed a fluorescence of lower than that emitted by the mature cells. In mature mast cells from rats and mice the fluorescence color induced with acid dyes except for thiazine red R, was dependent on the dye concentration. No or insignificant change of fluorescence was observed with the basic dyes.

Acids↗
PubMed1980

Inhibitory effect of a fluoride-containing amalgam on development of cavity wall lesions in vitro.

This study aimed to compare caries-like lesions produced aroung fluoride-containing amalgam and conventional amalgam fillings in vitro. Class V cavities were prepared in 90 extracted premolars, a fluoride-containing amalgam was inserted in 45 cavities (experimental group) and a conventional amalgam in 45 cavities (control group). After three months in an acidified gelatin solution, a longitudinal ground section passing through the cavity was prepared from each tooth. The sections were imbibed in water, quinoline and some in air before examination by polarized light microscopy. When imbibed in Canada balsam the sections were photographed and areas of demineralization in the enamel measured morphometrically. Some sections were studied by microradiography and electron microprobe analysis. Numerical scoring of the histological observations revealed significantly lower values for enamel and dentin cavity wall lesions in the experimental group, while the scores for the outer lesions were not statistically different between the two groups. The mean extension of enamel wall lesions was significantly lower in the experimental group, while no difference was observed in the outer lesions. A zone of increased mineralization in the enamel cavity walls was a frequent finding in the experimental group. This study has shown that fluoride-containing amalgam has an inhibitory effect on the development of experimental cavity wall lesions in vitro.

Dental Amalgam↗
PubMed1978

Penetration of ions from silicate cement restorations into Copalite--covered cavity walls.

This study aimed to asses the effect of silicate cement on Copalite -covered cavity walls in extracted human teeth. Class V cavities were prepared in 24 premolars and filled with silicate cement (Bio-Trey). Four cavities were unlined, the rest of the cavities were lined with 1 or 2 layers of Copalite before insertion of the restorations. After 6 months, 70-100 microns thick longitudinal sections of the teeth were studied by polarized light microscopy, microradiography and electron probe microanalysis. When imbibed in water or quinoline, a subsurface zone of altered birefringence was noticed in nearly all cavity walls. Nearly half of the cavity walls in the experimental groups showed a surface zone of increased radiopacity. In a few instances a subsurface radiolucent zone was present. By electron probe microanalysis F (0,4-3% by weight), Zn (1-4%) and Al (0,2-6%) were measured in the outer 10-60 microns of the cavity walls. The study shows that even with a double layer of Copalite, known to prevent microleakage, a desirable uptake of F and Al from silicate restorations into cavity walls can take place. Copalite does not prevent a phosphoric acid effect on the cavity walls.

Aluminum↗
PubMed1978

Fluorescence microscopic demonstration of rat mast cells stained with acid dyes.

The amphoteric acid dyes acid fuchsin, aniline blue WS, azocarmine G, fast green FCF, light green SF and the wholly acid dye thiazine red R were used for fluorochromy of mast cells in sections of formalin or alcohol-formalin fixed rat tongues. By ordinary light the mast cell granules were barely visible. By UV or blue light exitation, however, a selective, secondary fluorescence of varying intensity and contrast against the tissue background manifested itself. By thin layer chromatography each dye revealed 3--7 components. Except for aniline blue WS, the main component(s) of each dye conferred to the granules the same fluorescence as the corresponding whole dye. These results of fluorochromy, together with the findings of methylation and deamination experiments, allowed the assumption that the anionic groups of the dyes were bound to unoccupied basic groups of the mast cell granules.

Animals↗
PubMed1976

Electron probe microanalysis of secondary carious lesions adjacent to silicate fillings.

Secondary caries associated with silicate fillings is characterized by lesions at the tooth surface and lesions of the cavity wall. The mineral content of the cavity wall lesions and the penetration of elements originating from the silicate fillings were studied in experimental in vitro and in vivo lesions as well as in natural carious lesions. Dentine wall lesions, where microradiographs had shown increased radiopacity relative to intact tissue, exhibited increased Ca and P values. Elements derived from the silicate fillings were regularly found in enamel and dentine. The concentrations of fluorine (F) and of zinc (Zn) amounted to 2-3% by weight close to the cavity wall and decreased gradually to less than 0.1% at depths of 600 mum and 400 mum, respectively, from the cavity. Aluminum (Al) most often occurred in a 20-40 mum-wide zone, showing a maximum concentration of 2-3% near the cavity. Sulfur (S) was often present in the dentinal cavity walls of natural secondary caries, but not in the in vitro specimens. The findings indicate that F released from the silicate filling significantly modifies the progress of a carious lesion in the adjacent enamel and dentine. Through its tendency to form complexes with F, Al may possibly enhance the cariostatic effect of F.

Aluminum↗
PubMed1976

Experimental in vitro lesions adjacent to composite restorations in etched cavities.

Class V cavities and wedge-shaped cavities simulating erosions were prepared in thirty extracted, permanent human teeth. After being etched for 2 minutes with the pertinent cleanser, the wedge-shaped cavities were restored with Enamelite or Restodent. The Class V cavities were etched with 50% phosphoric acid and restored with HL-72. Artificial lesions around the fillings were produced by immersing the teeth in an acid-gelatin system. Ground sections of the teeth with the fillings in situ were studied by polarized light microscopy and microradiography. All the teeth showed "outer lesions," whereas the occurrence of a "wall lesion" was a rare exception.

Composite Resins↗
PubMed1976

Root caries: distribution and uptake of elements in lesions adjacent to silicate or amalgam restorations.

In carious lesions adjacent to silicate or amalgam restorations outer lesions of the cementum showed the same content and distribution of Ca, P, Mg, and S as did primary lesions in this area, but differed from these in having an increased content of Zn, Al, and probably F (silicate cases) and Zn, Sn, and Cu (amalgam cases). The cementum walls showed an uptake of ions largely similar to that previously described in dentinal walls.

Aluminum↗
PubMed1975

Electron probe microanalysis of secondary carious lesions associated with silver amalgam fillings.

Secondary caries associated with silver amalgam fillings is characterized by outer lesions and cavity wall lesions. In this study the content of minerals and the penetration of elements from the amalgam into such lesions were analyzed. In sections of 11 teeth including cases of natural secondary caries and experimental in vitro and in vivo lesions around silver amalgam fillings the distribution of Ca, P, Mg, Zn, Sn, Cu, Ag and Hg was studied by means of two-dimensional X-ray images, linear scans and point analyses. Dentine wall lesions where microradiographs had shown increased radiopacity relative to intact tissue, exhibited considerably reduced Ca and P values. The outer portion of the radiopaque areas contained 5--8% Zn and Sn, decreasing to less than 0.1% at a varying distance up to 130 mum from the cavity wall. Hg was not detected, nor was Ag, except in one specimen. The increased radiopacity of this zone as observed on microradiographs is, therefore, obviously caused by the presence of Zn and Sn. Zn and Sn had also penetrated into the moderately demineralized enamel lesions, but the concentrations were generally lower than those observed in the dentine.

Calcium↗