摘要:

The administration of a glucose-rich diet to a group of O-M rats was followed by development of massive amounts of plaque. The predominating microorganism isolated from these plaques was a filamentous form identified as Actinomyces viscosus. A. viscosus, growing in dialyzed actinomyces broth (BBL) containing excess of glucose, produced a viscous culture from which extracellular slime was isolated by precipitation with ethanol. Fractionation of the extracellular slime on DEAE-Sephadex revealed the presence of two major components, one of which contained mainly glucose, while the other was more complex and contained glucosamine, hexose and protein. Antibodies could be produced against extracellular antigens which were found to be present in the slime but only accounted for a minor portion of the material.

ISSN:0008-6568    

DOI:10.1159/000260109

出版商:S. Karger AG    

年代:1974

数据来源: Karger

摘要:

The slime-producing microorganism A. viscosus Ny1 was tested on its plaque-forming ability and its cariogenicity in rats fed on glucose or sucrose diets. In mono-associated as well as SPF O-M rats, strain Ny1 caused considerable plaque formation on both diets. The role of the resident microflora on the establishment of strain Nyl was investigated by varying its composition with antibiotics. It was found that pre-experimental treatment with erythromycin prevented the establishment of strain Ny1 in SPF rats. In mono-associated rats, strain Ny1 caused no smooth surface caries and little fissure caries. However, in SPF rats, the interaction of strain Ny1 with the resident microflora resulted in considerable smooth surface and fissure caries on both diets. Smooth surface caries was greater on the sucrose diet.

ISSN:0008-6568    

DOI:10.1159/000260110

出版商:S. Karger AG    

年代:1974

数据来源: Karger

摘要:

The uptake and release of sodium, orthophosphate, calcium and strontium from human dental enamel have been studied using radioactive techniques. The uptake of these elements were found to be both hetero-ionic and iso-ionic, but preferentially iso-ionic in the case of sodium, orthophosphate and strontium. However, the uptake of calcium was preferentially hetero-ionic. Also strontium was not observed to be permanently taken up by dental enamel. Strontium in dental enamel could exchange with either strontium or calcium in the surrounding solution at practically the same rate.

ISSN:0008-6568    

DOI:10.1159/000260111

出版商:S. Karger AG    

年代:1974

数据来源: Karger

摘要:

The tetrazolium technique was applied in tissue sections from sound and carious enamel plaque on human teeth to represent the histotopochemical distribution of activity for numerous enzymes of the Embden-Meyerhof pathway, the pentosephosphate and citrate cycle, and the glycerophosphate cycle. GAPDH, LDH, G6PDH, ME, MDH, SDH, and NAD-IDH were found in all samples from sound enamel plaque; NADP-IDH appeared in a few. In plaque from carious enamel, all enzymes tested were found constantly in all samples. There was high enzyme activity in the outer bacterial layer of plaque from sound enamel, whereas the bacterial layer adjacent to the enamel showed substantially less activity. In contrast to the other enzymes, LDH generally showed a relatively low level of activity with signs of stronger activity in the inner layer adjacent to the enamel than in the outer layer. In plaque from carious enamel, the activity of the enzymes tested showed a definite increase from the outer to deeper layers, and was highest in the bacterial layer next to the enamel. The distribution pattern of LDH coincided with that of the other enzymes tested. A semi quantitative differentiation of enzyme activity in the two types of plaque showed that microorganisms in plaque from carious enamel have greater catalytic activity in carbohydrate metabolism than comparable microflora in plaque from sound enamel. From a functional point of view, the total biotope plaque was subdivided into further partial biotopes, characterized by different enzymic activities.

ISSN:0008-6568    

DOI:10.1159/000260112

出版商:S. Karger AG    

年代:1974

数据来源: Karger

摘要:

Root surface carious lesions on 99 teeth were evaluated as to morphologic distribution and histopathologic classification. Most lesions occurred on proximal surfaces and approximately 70% microscopically demonstrated carious progression characterized by dentinal tubular matrix destruction. Confirmation of the occurrence of a densely-mineralized surface layer was obtained by microradiography, as well as hypermineralization of dentinal tubules beneath the lesion.

ISSN:0008-6568    

DOI:10.1159/000260113

出版商:S. Karger AG    

年代:1974

数据来源: Karger

摘要:

Phenylketonuria is a rare inherited metabolic defect in which there is a deficiency of the liver enzyme phenylalanine hydroxylase. Unless this condition is diagnosed within the first few weeks of life, and treated with special diets which have a high carbohydrate content, but which are very low in phenylalanine, severe mental deficiency can result. 105 phenylketonuric (PKU) children, aged 10 months to 16 years, were examined to determine whether this special diet had any effect on the prevalence of caries in PKU children. It was concluded that caries experience in the PKU children examined was of the same order as that reported in normal children of comparable age.

ISSN:0008-6568    

DOI:10.1159/000260114

出版商:S. Karger AG    

年代:1974

数据来源: Karger

摘要:

In a combined microprobe-microradiography experiment the calcium concentration and the mineral content has been measured in sound, decalcified and in decalcified SnF2-treated enamel. The calcium content was estimated by the microprobe along the densitometric path of the radiography experiment. The results suggest the possibility that in the decalcified area a considerable amount (about 10–14 wt%) of the mineral is present either as precipitated ortho-phosphates or is adsorbed as Ca++ and HPO4 = ions. Only a few wt% of calcium is lost from lesion and surface layer. In enamel treated with stannous fluoride demineralization was less than in untreated specimen

ISSN:0008-6568    

DOI:10.1159/000260115

出版商:S. Karger AG    

年代:1974

数据来源: Karger

摘要:

The mineral content of enamel decalcified with and without preliminary F application was measured using quantitative microradiography. The effect of an aminefluoride solution and SnF2-containing solutions on the mineral content in the lesion and the surface layer was studied. The results showed that local application of the aminefluoride solution to sound enamel was more effective than SnF2; the demineralized area had a significantly higher mineral content in the lesion and a considerably thicker surface layer. There was no significant difference between the protective effect of both fluoride solutions on the mineral content of the lesion in the ‘white spot’ enamel groups. In the surface layer of the ‘white spot’ enamel groups, however, the SnF2 treatment was significantly more ef

ISSN:0008-6568    

DOI:10.1159/000260116

出版商:S. Karger AG    

年代:1974

数据来源: Karger

摘要:

A technique is described by which the distribution of lead and the lead content in human teeth has been measured by means of 3He++ 25 years), showing a tendency for a peak of lead concentration to form with age near the pulpal surface. The implications of these results are discuss

ISSN:0008-6568    

DOI:10.1159/000260117

出版商:S. Karger AG    

年代:1974

数据来源: Karger

ISSN:0008-6568    

DOI:10.1159/000260118

出版商:S. Karger AG    

年代:1974

数据来源: Karger