ISSN:0008-6568    

DOI:10.1159/000260630

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

A substance found in carrot, Daucus carota, with the ability to agglutinate Streptococcus mutans cells, was purified by means of affinity chromatography on immobilized whole S. mutans cells. The agglutinin was further characterized in order to determine the nature of the participating molecular entities in the binding reaction. The agglutinin was shown to be heat and trypsin stable, whereas treatment with dextranase destroyed its ability to agglutinate S. mutans cells. The cells, however, could be agglutinated after treatment with dextranase, but could not be agglutinated after treatment with heat or trypsin. The agglutination of S. mutans cells with carrot agglutinin was competitively inhibited by low molecular weight dextran. It was concluded that protein structures on the cell surface of S. mutans were essential for the binding of the carrot agglutinin. Furthermore, the agglutinin, isolated from D. carota, seemed to be carbohydrate in nature, presumably a dextran.

ISSN:0008-6568    

DOI:10.1159/000260631

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

The fluoride distribution was determined along the developing human fetal enamel of 7 maxillary first incisors taken from fetuses aged 5–9 months. The fluoride concentration in the enamel from teeth of fetuses aged 5–8 months, which contained only forming enamel was higher in the youngest enamel near the cervical margin than in the earliest formed enamel at the incisal tip. In the developing enamel from the teeth of the 9-month-old fetuses, however, after the initial decrease in fluoride concentration from the cervical margin towards the border between the forming stage and the maturing stage, there was a rise in fluoride concentration as the forming enamel began to rapidly mineralize to become maturing enamel. This pattern seems analogous in the comparable stages of enamel development to that previously observed in developing enamel from teeth of experimental anim

ISSN:0008-6568    

DOI:10.1159/000260632

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

Progress of lesions with time is important from a practical point of view, but especially because it provides information on the mechanism of the caries process. Firstly, a theoretical description of lesion progress with time is derived. It is based on the assumption that (1) steady-state diffusion during the caries process takes place through very tiny holes in the enamel surface, (2) inhibitors make the enamel surface insoluble and diffuse during the process inwards (the inhibitors, e.g. diphosphonates or fluorides may be coming from an external solution or may orginate from the enamel itself), and (3) the inhibitor blocks enamel dissolution effectively if the inhibitor concentration XL exceeds the fraction of surface phosphate sites XL*. The theory shows that lesion depth (r1) is about proportional to the third root of demineralization time (t), and can be written as r13 = αt + q, α and q being constants. Second, a comparison is made with experimental lesion depth data from various authors in artifical lesion systems. The results show that lesion progress in human and bovine enamel at pH 4, 4.5 and 5 is very well described by the above formula. This result indicates strongly that inhibitor action and inhibitor penetration are important during the caries process. From the experimentally determined slope a the apparent diffusion coefficient Dapp of the process is determined as ≈ 10––5 cm2s––1. This value is comparable to D of Ca++ and phosphate ions in aqueous solutions and indicates that ion transport during the process takes place in water-fill

ISSN:0008-6568    

DOI:10.1159/000260633

出版商:S. Karger AG    

年代:1982

数据来源: Karger

ISSN:0008-6568    

DOI:10.1159/000260634

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

The incidence of fissure caries was determined in Sprague-Dawley and Osborne-Mendel rats housed in a frequency-controlled feeding machine and fed diets containing 67% sucrose, maltose or corn starch. The effect on caries of reducing the sugar content of the diets to 35% and of supplying the sugars as 20% solutions to Osborne-Mendel rats was also observed. Caries was negligible in the rats fed a corn starch diet and there was a non-significant tendency for fewer lesions to appear in the rats fed maltose compared with sucrose. The high and low maltose diets produced less caries than the sucrose diets of the same strength, and the high sugar diets were associated with more caries than the low sugar diets. However, both of these trends were not statistically significant. No severe fissure lesions were detected in rats drinking either sucrose or maltose solutions and there was a non-significant trend for there to be fewer lesions in the sucrose group. No smooth surface lesions occurred in either group.

ISSN:0008-6568    

DOI:10.1159/000260635

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

219 Osborne-Mendel rats were weaned at the age of 19 days, inoculated with Streptococcus mutans and fed a cariogenic diet for 42 days. The control group received no treatment; the 6 study groups received applications of Duraphat®, Fluor Protector® or a placebo varnish once daily on either days 19–21 or 25–27. Caries was significantly reduced by both fluoride varnishes. The effect was most pronounced on recently erupted teeth, on which the varnishes were equally effective. Duraphat was more effective than Fluor Protector when applied to more mature teeth. Varnish without fluoride did not prevent c

ISSN:0008-6568    

DOI:10.1159/000260636

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

A urea-MFP mineralizing solution increased the average concentration of calcium in artificial plaque in 5 subjects from 7.6 to 219 μg/mg protein, but the concentration fell to 59.6 μg/mg protein during subsequent cariogenic glucose exposures. The concentration of phosphate rose from 5.4 to 107 μg/mg protein and then fell to 32.7 while fluoride rose from 0.008 to 7.62 and then fell to 4.27 μg mg protein. Following the cariogenic challenges, enamel beneath mineralized plaque showed an average increase in Knoop diamond indentation length of 4.3 μm (compared to 25.01 μm beneath unmineralized plaque) and no radiographic evidence of demineralization. Enamel softening was inversely related to the amount of mineral in the overlying plaque. When the maintenance was high, the development of experimental caries was virtually eliminated. Common ion suppression of enamel dissolution is the most likely explanation for the caries-protective e

ISSN:0008-6568    

DOI:10.1159/000260637

出版商:S. Karger AG    

年代:1982

数据来源: Karger

ISSN:0008-6568    

DOI:10.1159/000260638

出版商:S. Karger AG    

年代:1982

数据来源: Karger

ISSN:0008-6568    

DOI:10.1159/000260639

出版商:S. Karger AG    

年代:1982

数据来源: Karger