摘要:

The dental plaques of 20 young children were examined for bacteria having lytic activity against Streptococcus sanguis ATCC 10556, 10557, and 10558. Bacteria showing lytic activity against S. sanguis ATCC 10558 alone were isolated from dental plaques of all subjects. They were identified as Streptococcus mutansby their physiological characteristics and produced an extracellular enzyme that dissolved living cells of S. sanguis ATCC 10558, but not those of S. sanguis ATCC 10556 and 10557, Streptococcus salivarius ATCC 9222 and HHT, Streptococcus mitis ATCC 9811, Streptococcus milieu ATCC 10708, or Streptococcus mitior ATCC 903. However, this enzyme dissolved living cells of 43 (32.8%) out of 131 strains of S. sanguis isolated from dental plaques of all subjects at a rate similar to or higher than that against S. sanguis ATCC 10558 cells.

ISSN:0008-6568    

DOI:10.1159/000261044

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

The fluoride concentration in whole saliva and the effect of variations in salivary flow rate were studied in 5 volunteers after use of a chewing gum (Fluomin®) containing 0.25 mg fluoride as sodium fluoride. Basal fluoride concentration during 2 consecutive days ranged between 0.3 and 1.1 μmol/l. The salivary fluoride clearance was studied after chewing one piece of the gum. The clearance of fluoride showed three phases in the decline of the curve. The effect of multiple dosing of the fluoride gum was studied for 7 days, one piece of gum was chewed every 2nd hour during the day and whole saliva was sampled frequently. The subjects with a stimulated salivary flow rate ranging between 0.9 and 2.5 ml/min had a mean steady-state level of fluoride in the saliva ranging from 0.7 to 1.6 μmol/l. This was in contrast to the subjects with low salivary flow rate ranging between 0.4 and 0.6 ml/min, where the fluoride concentration ranged from 4.7 to 19.2 μmol/l. In a separate study, the fluoride concentration in plasma in 4 subjects was studied for 24 h following repeated use of 0.5 mg fluoride as two pieces of the gum 10 times a day. The plasma levels found ranged from 1 to 3 μm

ISSN:0008-6568    

DOI:10.1159/000261045

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Bovine dental enamel was demineralized in Ca- and phosphate-containing acetate buffers at pH 4.5, with and without albumin and fluoride. Demineralization in albumin-free solutions was followed by albumin treatment at pH 6.8 or 4.7. The mineral loss during demineralization was markedly reduced by the presence of albumin in the solution. Experiments with 14C-albumin showed qualitatively that the albumin penetrated about 100–120 μm into the porous enamel. The protein uptake after demineralization was pH-dependent: at pH 6.8 less albumin was taken up compared with at pH 4.7. The quantitative uptake during demineralization was comparable with the uptake after demineralization at pH 4.7. The albumin uptake showed a linear relationship with the concentration of protein in solution, both during and after demineralization. There was no measurable influence of fluoride on the quantitative albumin uptake during demineralizati

ISSN:0008-6568    

DOI:10.1159/000261046

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

The surface morphology of human enamel treated with pulsed, infrared laser radiation was examined using reflected light and scanning electron microscopy. Thin ( < 5μm) surface melts with a varying degree of surface macroroughening were produced for each of the four wavelengths studied (9.32, 9.57, 10.27, 10.59 μm) in the 10–50 J·cm––2 pulse energy density range with peak power densities reaching approximately 107–108 W·cm––2. Significant heat conductance under the surface melt was limited to a depth of approximately 10–20 μm. Tetracalcium diphosphate monoxide, Ca4(PO4)2O, was identified as being a component of the surface melt together with an apatite phase that had a reduced carbonate content when compared to normal surface enamel. Histological differences and shallower lesions were observed using polarizing light microscopy in artificial lesions formed in lased enamel when compared with control lesions. These results provide a greater understanding of the use of lasers as a potential preventative

ISSN:0008-6568    

DOI:10.1159/000261047

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

This study was designed to assess the effect of flavour and detergent in NaF and MFP dentifrices on the availability of fluoride in whole saliva after toothbrushing. Saliva samples were collected in 13 subjects at different times up to 60 min after brushing with controlled amounts of dentifrices with various compositions. The availability of fluoride in whole saliva was determined in terms of areas under the elimination curves (AUC) after linearization of the data by application of the Weibull function. This distribution provided the best quality of fit of all individual elimination data in contrast to commonly used data transformations. Analyses of variance showed a highly significant effect of individuals on the AUC values. Addition of flavour consistently reduced the AUCs whereas addition of detergent always increased the AUCs. The detergent had a negative effect on the observed intraoral hydrolysis of MFP. It was suggested that F–– AUC is a fundamental parameter for the cariostatic potential of F dentifri

ISSN:0008-6568    

DOI:10.1159/000261048

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

This investigation, comprising three studies, measured the effects of flushing with an acidic calcium phosphate solution (CPS) on the cariostatic benefits of fluoride. In the first two studies, the rats received fluoride in the drinking water (2.5 ppm F) after initiation of the caries challenge. In contrast, in the third study, the animals received treatments as oral flushing before initiation of the cariogenic challenge. In all three studies, rats that received CPS in conjunction with fluoride exhibited a numerically lower mean caries score than those that received H2O in conjunction with fluoride. Moreover, in the third study, the group receiving oral flushing of CPS followed by NaF (10,000 ppm F) for 3 successive days exhibited a significantly lower incidence of dental caries and higher concentration of enamel-bound fluoride than did the group treated with a H2O-NaF sequence. A significant negative association (––0.65) between fluoride and caries was noted when the dentition of all rats in the third study were conside

ISSN:0008-6568    

DOI:10.1159/000261049

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

The cariogenicity of two chocolate confections was compared using a rat caries model. One chocolate confection contained 5.6% w/w casein while the other contained 16.6% w/w casein. The levels of fat and sucrose were the same in both confectionery. The casein enrichment was achieved by replacing the 18% w/w non-fat milk solids used normally in the manufacture of milk chocolate with soluble sodium caseinate. Forty Sprague-Dawley male rats infected with streptomycin-resistant Streptococcus mutans consumed the chocolate diets either ad libitum or in a Konig/Hofer programmed feeder. Animals consuming the casein-enriched chocolate either ad libitum or programme-fed had significantly (p < 0.001) lower smooth surface and fissure caries scores than the animals consuming the normal chocolate. There was no significant difference in the mean final body weight, salivary output, or salivary protein, calcium or phosphate concentrations between the animals on the two chocolate diets. There was also no significant difference in the number of total organisms, streptococci or streptomycin-resistant S. mutans recovered from the swabs of the molar teeth of animals on both diets. The work confirms an earlier report of a topical anticariogenic effect of soluble caseinate and shows that it is possible to reduce the cariogenicity of chocolate by caseinate supplementation.

ISSN:0008-6568    

DOI:10.1159/000261050

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Forty-six deciduous teeth from caries-free children who had been exposed to systemic fluoride tablet treatment (0.5–1 mg F–– 1,000 ppm in the fluoride group as compared to < 200 ppm in the control group. The structural and chemical findings showed that the tablet regime was capable of producing fluorotic lesions which may have been modified in molar teeth by the gel treatments. It is suggested that these observations should be taken into account when considering doses to be recommended for fluoride preventive prog

ISSN:0008-6568    

DOI:10.1159/000261051

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Radiographs for 15-year-old children in 1974/75, 1976/77 and 1983/84 were collected and scored for approximal caries. Information on the subsequent treatment of the same surfaces was obtained from the children’s treatment records. Approximately 15% of enamel lesions were filled in the beginning of the study period, while only 9% were filled by the end of the study period. A similar change was found for lesions in the outer half of the dentine. The number of lesions in the inner half of the dentine was too small to allow any conclusio

ISSN:0008-6568    

DOI:10.1159/000261052

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Data from a longitudinal, observational study of diet and dental caries were analysed to assess the relative cariogenicity of starch and sugars. The correlation between 2-year DMFS caries increment and weight of daily intake of sugars was positive and statistically significant, while the corresponding correlation for starch was weakly negative after controlling for confounding variables. The difference in the possible relative cariogenicity of starch and sugars occurred, however, almost entirely in fissure surfaces and was not observed in approximal surfaces. Children (n = 27) with high starch/low sugars intake had lower caries increments than children (n = 32) with low starch/ high sugars intake, but these differences were not statistically significant. The high-starch/low-sugars eaters consumed more energy but ate less frequently than the low-starch/high-sugars eaters. However, partial correlation analyses revealed that differences in frequency of eating could not explain the trend towards a stronger relation between sugar intake and caries than between starch intake and caries development.

ISSN:0008-6568    

DOI:10.1159/000261053

出版商:S. Karger AG    

年代:1987

数据来源: Karger