摘要:

In a study of the saliva-induced aggregation of Streptococcus mutans, it has been found that saliva pretreated with wheat germ agglutinin (WGA), a lectin with a high specificity for binding to N-acetylglucosamine (GlcNAc), did not induce the aggregation of S. mutans strains AHT, IB, and V-100. GlcNAc blocked the effect of WGA and restored aggregating activity to some WGA-pretreated saliva supernatants. The solution obtained by dissolving the precipitate from saliva treated with 256 μg/ml WGA in buffer containing 200 mM GlcNAc and 1 mM CaCl2, also aggregated S. mutans. The results suggest that WGA reversibly binds to a salivary aggregating factor containing GlcNAc

ISSN:0008-6568    

DOI:10.1159/000260391

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

By means of the Warburg technique it was studied whether addition of xylitol interferes with sucrose degradation in human saliva. For this purpose, different concentrations of xylitol were added to incubated saliva-sucrose samples. An inhibition of sucrose degradation was not obtained under both aerobic and anaerobic conditions. Therefore, it seems to be of doubtful value to produce, e.g., sweets consisting of a sucrose-xylitol mixture and to expect that these products will have caries-preventive properties.

ISSN:0008-6568    

DOI:10.1159/000260392

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

Both free and adsorbed lactoperoxidase (LPO) were shown to produce the bacterial inhibitor, hypothiocyanite ion (OSCN––) in approximately equal capacity. In human salivary sediment OSCN–– ions are rapidly decomposed, even at pH 7.0 were OSCN–– ions otherwise are stable, indicating the presence of destructive agencies in sediment. Hypothiocyanite ions formed within the sediment inhibited acid formation clearly more than OSCN–– ions applied from outside. Iodide ions present in saliva inhibited competitively OSCN–– i

ISSN:0008-6568    

DOI:10.1159/000260393

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

When testing the plaque-inhibiting effect of enzyme preparations in dentifrices the difficulty arises how to differentiate between enzyme inhibition and mechanical effect of brushing. To differentiate between these two effects, in the present investigation the influence was assessed of frequent scorings (3/week) on patient behaviour related to the plaque-reducing effect of 3 toothpastes (patient’s usual one, test, and placebo paste). The tests were performed double blind on 9 subjects over a 50-day period. The results of a factorial analysis of variance showed the plaque-reducing effect (p < 0.05) of the active toothpaste for all plaque sites in the Silness-Löe Index system, as well as its influence on the health of the surrounding gingiva. From the results it may be concluded that these reducing effects were caused by the enzyme activity of the amyloglucosidase and glucose oxidase in the test toothpas

ISSN:0008-6568    

DOI:10.1159/000260394

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

In a short-term animal test, 48 Osborne-Mendel rats were divided into three groups (one control, one placebo and one active), in which experimental toothpastes were applied 3 times weekly. Histological and statistical evaluation indicated the significant caries-reducing effect of the amyloglucosidase and glucose oxidase containing active toothpaste in comparison with the two others. These results confirm the effects found in other clinical investigations.

ISSN:0008-6568    

DOI:10.1159/000260395

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

A method for the determination of the diffusion coefficient, D, of solutes in the separated aqueous and residual phases of 24-hour human dental plaque is described. The separated plaque components were placed in tubing (inner diameter 0.49 mm), pulsed at one end with radiotracer, and horizontal diffusion was continued at 37 or 5 °C for 5–17 h. The results indicate that the diffusion of 14C-sucrose and 14C-inulin in plaque fluid was similar to that in water, while the diffusion of 14C-starch was unexpectedly greater than in water. The D values for the three carbohydrates studied were inversely related to their molecular weights. In plaque fluid, the diffusion of ionic species, bicarbonate, acetate, lactate, butyrate as sodium salts, was less than in water. In the plaque residue, the diffusion was restricted in relation to the packing density of the residue. While the diffusion into plaque of readily fermentable carbohydrate was not restricted, that of their bacterial metabolic products was impeded, consistent with the rapid fall and slow rise in plaque pH, known to occur after exposure to fermentable carbohydra

ISSN:0008-6568    

DOI:10.1159/000260396

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

The influence of localization, posteruptive age and ethane-1-hydroxy-1.1 diphosphonate (EHDP) on artificial caries and its remineralization have been studied in human premolars. The depth of the lesions did not depend on the posteruptive age of the teeth, but on the localization on the teeth, presumably as a result of differences in morphological structure. At 30 μm from the surface of the enamel, an indication for a higher birefringence exists at a posteruptive age of 1 year than later on, suggesting a significantly higher de-mineralization which can be more fully remineralized, leading, in turn, to a lower birefringence. EHDP seems to stimulate, rather than to inhibit remineralization of artificial caries lesions in premolars with a posteruptive age of 1–5 yea

ISSN:0008-6568    

DOI:10.1159/000260397

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

In this study a mathematical model for the caries process is presented. It includes diffusion of ions, dissolution of mineral and complexation of ions. The conclusions from experiments with the model are that the relative stability of the surface layer of enamel can be explained by (1) a gradient in the solubility product of the enamel, (2) a gradient in the rate constant of the dissolution reaction or (3) a gradient in the porosity of the enamel. The outcomes of the simulations suggested that the minimum set of conditions that is necessary to obtain artificially a caries-like lesion is that the bulk solution should be relatively saturated with respect to apatite. This has been confirmed by an in vitro caries experiment.

ISSN:0008-6568    

DOI:10.1159/000260398

出版商:S. Karger AG    

年代:1979

数据来源: Karger