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Biomedical subjects

E Hals

Publications and source records attributed to E Hals.

At least 19 recordsLinked to original sources
PubMed1991

Column-like structures of human dentin in carious and artificial lesions.

Serial sections of 36 human teeth with minor to medium-sized carious lesions, adequate sections from previous studies of artificial lesions adjacent to fillings of amalgam (AM), silicate cement (SI) and glass ionomer cement (GI) were studied by ordinary light microscopy and microradiography. Six artificial primary root lesions were included. In carious lesions, dentin columns were visible in the demineralization zone and partly also in the translucent/radiopaque zone. A typical feature of the artificial lesions adjacent to SI fillings was highly radiopaque columns alternating with radiolucent ones. In the GI group such columns were seen at the cavity wall and the advancing front of the outer lesion. In the AM group dark columns were unveiled as pegs in the latter localization. The findings led to the assumption that the dark columns of intact dentin are preferred pathways of acid diffusion in artificial and, possibly, carious lesions. Increased radiopacity of columns in the SI and GI groups is explained by continued exposure of the tooth surface to fluoride dissolved from these fluoride-rich filling materials.

Dental Amalgam↗
PubMed1990

Column-like structures following the course of tubules in human dentin.

Sections, 60-180 microns thick, of permanent teeth, intact or with minor fillings, were cut parallel or transversal to the course of the dentinal tubules. Some teeth were demineralized, embedded in paraffin wax, cut in series, and stained with toluidine blue pH 5.6, hematoxylin-eosin, or PAS. Altogether, sections of 90 teeth were examined by ordinary and polarized light microscopy and contact microradiography. Alternating light and dark bands, usually 8-30 microns wide, extended from the pulpal border along the course of the tubules, gradually increasing in width, fading in the mantle dentin. Cross-sectioned bands appeared as dark and light "discs". This was the background for the term "columns". In the dark columns, usually exhibiting crowding of tubules, the intertubular dentin was dark and radiolucent; in the light columns, light and radiopaque. Dark columns contained a high amount of GAGs, assumed to have exerted an inhibitory effect on their mineralization. The columns probably represent structural elements in the architecture of dentin, possibly offering resistance against mechanical stress. It was suggested that the columns might depict functional differences in the matrix secretion and mineralization capacities of odontoblasts.

Adult↗
PubMed1988

Column-like structures following the course of dentinal tubules in bovine, red deer, and rat teeth.

A material of bovine, red deer, and rat incisors was investigated, with emphasis on the bovine teeth. Both ground sections and paraffin wax sections of demineralized material were used. The sections were investigated by ordinary and polarized light microscopy and contact microradiography. In the bulk of the dentin irregular column-like light structures, alternating with largely similar, but dark, columns, followed the course of the dentinal tubules from the pulpal border to just below the mantle dentin. Each column, 10-100 micron in diameter, contained a highly varying number of tubules. The difference between light and dark columns was mainly related to the intertubular dentin of the globules of which they were composed. Light columns were slightly more mineralized than the dark ones and seemed to contain fewer GAGs, but more glycoproteins. A difference in fiber direction between light and dark columns was also evident. To the authors' knowledge these structures have not attracted the attention of previous workers.

Animals↗
PubMed1988

X-ray microanalysis of dentin: a review.

The aim of this review was to present a condensed summary of the literature on X-ray microanalysis of dentin, including both energy-dispersive (EDS) and wavelength-dispersive (WDS) analysis. Estimations of concentrations by XMA of dentin should be regarded as semiquantitative values. The Ca level in rat odontoblasts was elevated in the secreting end of the cell body. In predentin Ca accumulated at a concentration of 2% that of mineralized dentin. In coronal dentin the peritubular areas were hypermineralized (Ca, P, Mg). Primary caries lesions showed a decrease of Ca, P, Mg and Cl, and usually an increase of S and Zn. The mineralized surface often present contained especially high concentrations of F and K. Considerable uptake of various ions in cavity walls exposed to filling materials was assessed: from silver amalgam, Zn and Sn, from silicate cement and glassionomer cement F, Al and Zn, and from zinc oxide-eugenol cement, Zn. The highest F concentrations following topical application were found with solutions of TiF4 and with the varnishes Duraphat and Fluor Protector. Dentin wall lesions adjacent to amalgam fillings exhibited considerably reduced Ca and P values, but concomitantly considerable amounts of Zn and Sn, that explained the increased radiopacity seen in some microradiographs.

Dental Caries↗
PubMed1985

Electron probe study of human and red deer cementum and root dentin.

A topographical description of the concentration profiles of Ca, P, Mg, Zn, F, S, and K in human and red deer cementum and root dentin is given. The concentrations reported should be regarded as semiquantitative values. A downward slope of the Ca, P and Mg profiles toward the pulpal cavity seemed largely to correspond with the secondary dentin. Marked elevations of the Zn profiles, modest elevations of the F profiles, and in a few instances of the S profiles, toward root surface and pulpal cavity were registered. In a couple of scans a slight elevation of the K profile toward the root surface ws observed. A high degree of concordance in human and red deer teeth was ascertained.

Adult↗
PubMed1985

Electron probe study of coronal dentin in red deer.

A topographic description of the concentration profiles of Ca, P, Mg, Zn, F, S and K in coronal dentin of red deer is given. The concentrations reported should be regarded as semiquantitative values. An area along the mesiodistal axis of the crowns showed lower concentrations of Ca and P and higher concentrations of Mg than the surrounding bulk of dentin. The inner dentin revealed downward slopes of the Ca, P and Mg profiles toward the pulpal cavity, whereas the Zn, F and usually also the S profiles showed elevations. Incidental findings were elevations of S and K profiles near the worn incisal edges. The walls of giant tubules, which are frequent in red deer dentin, showed in many cases modest elevations of the Ca, P, Mg and Zn profiles. The lumina of these tubules revealed in a few instances elevation of the S profiles.

Animals↗
PubMed1984

Microradiographic and polarized light study of red deer root dentin with special reference to occurrence of giant tubules.

Radiolucent bands following the course of the dentinal tubules were observed in sections of undemineralized roots of permanent red deer incisors. Some of these bands, previously unreported in mammalian root dentin, contained giant tubules similar to those described earlier by the author in the coronal dentin of this animal. The root giant tubules initiated with funnel-shaped orifices at the border of the pulpal cavity and, generally, terminated in the peripheral dentin, whereas a few penetrated into the cementum. Whether the giant tubules should be considered to be anomalous dentinal tubules or a different type of structure could not be determined. The distinction between root giant tubules and accessory canals being part of the apical ramification did not represent any problem.

Animals↗
PubMed1984

Scanning electron and incident light microscopy of giant tubules in red deer dentin.

Incisal and cuspal teeth from red deers 2 1/2-6 1/2 yr of age were used in this study. Incident light microscopy was used for screening of the specimens with respect to presence of orifices and exposures of giant tubules. Scanning electron microscopy (SEM) was used for study of structural details. For SEM the specimens were pretreated with a 1% solution of NaClO for 2 or 20 h. One specimen was in addition exposed to a 35% solution of phosphoric acid for 30 s. Two teeth received no pretreatment. Many incisal/occlusal exposures of giant tubules were more or less blocked by a dense, probably mineralized, substance, whereas others were filled with spherical bodies, probably microorganisms. The walls of the pulpal chambers and root canals revealed an abundance of orifices of giant tubules. They were funnel-shaped with circular or oblong pulpal outlines, the diameters of which in untreated specimens ranged from 15 to 100 microns.

Animals↗
PubMed1983

Observations on giant tubules in human coronal dentin by light microscopy and microradiography.

Human coronal dentin was studied by light microscopy and microradiography. The material comprised 50 permanent and 10 primary anterior teeth and microradiographs of 63 primary anterior teeth from a previous study. Both intact and worn teeth were examined. Ground sections in the long axes of the crowns in the buccolingual and mesiodistal planes were prepared, as well as transverse sections. A few crowns were also examined in toto. A system of giant tubules extending from the border of the pulpal cavity could be followed, though not continuously, through the secondary and primary dentin almost to the incisal dentinoenamel junction was observed. The lumina of the tubules were 5-40 microns wide and bordered by an approximately 10-microns-wide, usually hypermineralized rim of dentin in which only a few dentinal tubules were clearly discernible. The giant tubules were located along the mesiodistal axes of the teeth. The number of such tubules varied between 0 and 30.

Cuspid↗
PubMed1983

A light microscopical and microradiographic study of coronal dentin in red deer with special reference to the occurrence of giant tubules.

The coronal dentin of red deer (Cervus elaphus L.) was studied by light microscopy and microradiographyy. The material consisted of incisors from 10 animals, 2 1/2-6 1/2 years of age. Sections in the long axes of the crowns in the buccolingual and mesiodistal planes were prepared, as well as transverse sections. A few crowns were also examined in toto. A system of giant tubules of the same type as in human dentin is described. It was, however, characterized by more regularity in the number and the morphology of the tubules. As in human dentin, the giant tubules extended from the border of the pulpal cavity and could be followed, though not continuously, through secondary and primary dentin almost to the incisal dentinoenamel junction. Up to 60 giant tubules could be counted in the mesiodistal axis of the dentin. Contrary to the situation in man, areas of interglobular dentin were abundant in the crowns.

Animals↗
PubMed1983

Polarized light study of giant tubules in human and red deer coronal dentin.

Previously described giant tubules in human and red deer coronal dentin have been subjected to a study by polarized light microscopy. Structure of the giant tubules was similar in both species. The lumen of each tubule was bordered by a 5-15-micrometers-thick collagenous mantle in which the fibers were orientate parallel to its long axis. In a circular dentin area encompassing the mantle, the course of the collagen fibers might be characterized as a winding of fibers around the cylindrical mantle. This structure of the giant tubules conforms with that described earlier in the rudimentary maxillary canine of a red deer. Thus, such tubules do not represent a rare anomaly, but occur regularly in both human and red deer coronal dentin.

Animals↗
PubMed1981

Elastic (pseudoelastic tissue in arterioles of the human and dog dental pulp.

Formalin-fixed pulps from seven human and five dog teeth were investigated for the occurrence of vascular elastic tissue with special reference to the difference between elastin and pseudoelastica. The latter term denotes structures which show the histochemical and fluorescence microscopic properties of collagen, but also bind the so-called elastica stains. Human aorta, and aorta, lips, tongues and gingiva from dogs served as control material. Whereas conventional elastica stains, in this study represented by orcinol-new fuchsin, only differentiate elastic tissue and collagen, a thiazine red R fluorescence method also permits differentiation between elastin membranes and pseudoelastica. Other methods for light and fluorescence microscopy verified this conclusion. Pseudoelastic fibers/membranes occurred in arterioles of both human and dog pulps, but were more frequent in the latter. The distribution of these elements in the arteriolar walls was different in the human and dog pulp. No elastin elements were observed.

Adolescent↗
PubMed1980

The structure of experimental in vitro lesions around glass ionomer cement restorations in human teeth.

Class V cavities were prepared at the amelo-cementum junction in sixty-eight extracted human teeth. Fifty-one were filled with glass ionomer cement (ASPA). 'Secondary carious' lesions were produced around thirty-five of the restorations by exposure to acidified gelatin. Thirty-three teeth served as controls of the effect of the preparation procedure, the conditioner, the ASPA liquid and the filling material proper on the cavity walls. Sixty 120 micrometers-thick longitudinal sections from the teeth with the restorations in situ were studied by polarized light microscopy and microradiography. The glass ionomer cement caused by itself a narrow zone of increased radiopacity in the dentine cavity wall. The 'secondary caries' pattern consisted of a subsurface outer lesion and a subsurface wall lesion as observed previously in corresponding experiments with silicate fillings. Outer lesions in enamel were more frequent than with silicate cement. In the cementum all the experimental teeth showed outer lesions. The wall lesions extended only slightly beyond the level of erosion of the restorations. Between the wall lesions (in dentine) or outer lesions (in cementum/dentine) and the surface of the cavity wall, a zone of increased radiopacity was found, assumed to be due to reprecipitation of Ca and P promoted by release of fluoride from the filling material.

Acid Etching, Dental↗
PubMed1980

The in vitro effect of a glass ionomer cement on dentine and enamel walls. An electron probe and microradiographic study.

Glass ionomer cement (ASPA) was inserted in unconditioned class V cavities or in contact with polished ground surfaces of enamel and dentine in twelve teeth. Ground sections of all teeth were examined by microradiography, and four of the sections submitted to electron probe microanalysis. A narrow outer zone of increased radiopacity in the dentine walls was explained by a 5--10% increase of Ca and P. In some sections this zone covered a partly demineralized subsurface zone. The concentrations of F and Al in enamel and dentine were similar to or approximately 0.3% and 1.5%, respectively, decreasing to less than 0.1% at a distance of 16--80 microns (F) and 8--24 microns (A) from the surface. Both F and Al penetrated deeper into the dentine than into the enamel. Decreased Zn values, sometimes concomitant with increased Ca, P and Mg values, were in some instances observed in an outer narrow zone of the dentine walls. It is assumed that like silicate cement, glass ionomer cement must have anticariogenic properties, due to uptake of F and Al in cavity walls.

Calcium↗