ISSN:0008-6568    

DOI:10.1159/000261074

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Acesulfame, a structural analogue of saccharin, like the parent compound, markedly decreased the sorbitol- and mannitol-dependent growth rate and growth yield of Streptococcus mutans NCTC 10449 and also decreased the amount of acid produced from these hexitols by the organism. One mechanism by which acesulfame may exert these effects is by competitively inhibiting the interaction of NAD(H) or NADP(H) with a number of pyridine nucleotide-dependent oxidoreductases found in hexitol-adapted cells. Sodium fluoride appeared to act synergistically with both saccharin and acesulfame in serving to decrease both the hexitol-dependent growth rate and growth yield of the organism and also the total amounts of organic acids produced from sorbitol and mannitol. The synergistic negative effects exerted upon hexitol metabolism by saccharin, acesulfame, and fluoride may be due to their collective role in decreasing intracellular levels of phosphoenolpyruvate (PEP), thus interfering with the PEP-dependent transport of sorbitol and mannitol into the cell.

ISSN:0008-6568    

DOI:10.1159/000261075

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The sucrose concentrations in saliva and the pH values of dental plaque were determined after a rinse with 0.6 mol/l sucrose in 10 subjects. The sucrose concentrations in saliva at 1 and at 5 min were significantly (p < 0.05) correlated to the hydronium ion concentration in the plaque material at 20 and 30 min after the rinse. A similar relationship was found between the sucrose concentration at 2 min and plaque hydronium ion concentration at 20 min, and between the sucrose concentration at 10 min and the plaque hydronium ion concentration at 30 min. It was concluded that factors influencing the early phase of salivary sugar clearance have an effect on the extent of the subsequent increase in the hydronium ion concentration in dental plaque, and thus may be important determinants in dental caries.

ISSN:0008-6568    

DOI:10.1159/000261076

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The constant composition crystallization technique has been used in conjunction with surface hardness and radiographic methods to investigate kinetic and physical aspects of remineralization of artificial carious lesions in bovine enamel in vitro. The kinetic data indicate that the remineralization of surface-softened enamel occurs more rapidly than that in subsurface demineralized white spots. The remineralization of all types of artificial lesions is associated with considerable surface rehardening. For shallow lesions, the relationship between surface hardening and remineralization is linear, however, this correlation breaks down in more advanced lesions. Importantly, the maximum rehardening of carious lesions appears to be related to their initial degree of acid demineralization.

ISSN:0008-6568    

DOI:10.1159/000261077

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

An in vitro pH-cycling experiment was completed to determine the effect of the timing of fluoride toothpaste application on de- and remineralization. Both initially sound enamel and artificially produced enamel lesions were subjected to a pH-cycling scheme. The lesions were either formed in an undersaturated calcium-phosphate-fluoride-acetate system (CPF lesions) or in a MHDP-containing lactate buffer (MHDP lesions). The two systems produced subsurface demineralization which differed in porosity, depth and surface layer characteristics. Changes in the enamel mineral content were assessed either by microhardness evaluation of the specimens at the end of the cycling period or by calcium uptake and loss during the pH-cycling period. The results show that a fluoride dentifrice treatment is very effective in inhibiting lesion formation in initially sound enamel as well as in inhibiting lesion progression. The latter was found to be primarily due to a significant decrease in mineral loss during the demineralization cycles. This observation was made irrespective of the timing of the fluoride dentifrice treatment, which was either given before or after the demineralization challenge. For the CPF lesions this inhibition was between 40 and 50%, while the corresponding value for the MDHP lesions was 15–30%. Differences between the two lesion types were also found in the dentifrice effect on lesion remineralization. In the case of the CPF lesions a small inhibition of mineral deposition was observed, while in MHDP lesions the fluoride treatment enhanced the remineralization. These observed differences are explained in terms of the differences in characteristics between these two types of lesion

ISSN:0008-6568    

DOI:10.1159/000261078

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

A pH-cycling model has been used to examine the reactivity of fluoride dentifrices and rinses with subsurface carious lesions in vitro. Measured parameters included fluoride uptake, remineralization, surface hardening and the distribution of acquired fluoride. In the study, all fluoride treatment groups exhibited increased remineralization relative to placebo and demineralization-only controls. In general, remineralization paralleled the total fluoride uptake, but the relationship was not one to one. The rank ordered efficacy of the fluoride topicals was found to be NaF dentifrice > remineralization solution = NaF + MFP dentifrice > MFP dentifrice > placebo. Analysis of the acquired fluoride distributions suggested that fluoride was incorporated throughout lesions under dynamic conditions.

ISSN:0008-6568    

DOI:10.1159/000261079

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

In an intraoral cariogenicity test model the influence of the temperature of the extraoral immersion solutions on both the demineralization of enamel and the pH drop of the plaque was studied. Ten volunteers wore the appliance for 3 weeks, except during 3 daily extraoral immersions of 15 min in a 3% sucrose solution. One side of the appliance was immersed in a solution at 37 °C, the other side in the same solution at room temperature (approximately 20 °C). The pH drop caused by plaque in situ as well as by plaque collected and suspended after the experiment was significantly faster at 37 °C. The lesions produced at this temperature were deeper and more demineralized. The rate of demineralization was almost twice as high at 37 than at 20 °C. Extraoral immersions at 37 °C are recommended to simulate in vivo conditions during immersion; in addition this procedure may shorten the experimental pe

ISSN:0008-6568    

DOI:10.1159/000261080

出版商:S. Karger AG    

年代:1988

数据来源: Karger

ISSN:0008-6568    

DOI:10.1159/000261081

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Past caries experience as expressed by means of the DIMFT index was studied in 1982–1983 in an adult, high-caries Finnish population. The random sample for the survey comprised 1,600 adults, 400 in each age group of 25, 35, 50 and 65 years. A total of 1,275 subjects (80%) were clinically examined, and of these 941 had one or more remaining permanent teeth. Of the remaining teeth, approximately 40% were sound in all four age groups. The corresponding percentage of teeth with open cavities varied only slightly, being highest (18%) at the age of 50 years and lowest (13%) in the 35-year-olds. The percentage of filled teeth decreased with age at the expense of increasing proportions of teeth indicated for extraction. When the missing teeth of the dentate persons were included in the analysis, the proportions of both sound, decayed and filled teeth were found to decrease with age. When the missing teeth of both the dentate and the edentulous subjects were included, the corresponding analysis revealed a substantial decrease in caries treatment needs with advancing age. It was concluded that the generally held view of caries experience being reduced with age may not be due to a decreasing caries activity but to the reduced number of remaining teeth. The constant proportion of remaining teeth being in need of repair was suggested to indicate that caries preventive measures would be needed by adults as well as by children and teenager

ISSN:0008-6568    

DOI:10.1159/000261082

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The purpose of the study was to investigate caries of primary teeth and some associated back ground factors in a group of 580 nursery school children. The age of the children ranged from 3 to 8 years; 83% of them were of African origin, the remainder being Asians and Arabs. The mean dmft score of Africans was 2.3 and that of the other ethnic group was 4.3; 37% of the children showed zero caries experience. Boys of Asian and Arab origin had significantly higher dmft scores than the others. The most common location of caries lesions was on the proximal surfaces. The mean dmft score in the group of children with high socioeconomic standard (SES) was slightly higher compared to the children with lower SES, but the difference was not significant. The experience of caries found in this study is higher than that reported in most African studies.

ISSN:0008-6568    

DOI:10.1159/000261083

出版商:S. Karger AG    

年代:1988

数据来源: Karger