摘要:

With standardized plaque sampling techniques, bacterial populations were studied on the fissures of 500 unrestored lower first permanent molars in 279 children 6–7 years old at the beginning of a 2-year period. Samples were taken every 6 months. Actinomyces species, Veillonella, Streptococcus mutans, Streptococcus sanguis, and Lactobacillus species were detected in a range from 300 to 5 × 107 colony-forming units per plaque sample. S. mutans and lactobacilli were found to be the most numerically stable of the species investigated, and high numbers of these two were associated with the development of fissure cari

ISSN:0008-6568    

DOI:10.1159/000260843

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

The ATP content of 10 dental plaque samples changed rapidly during starvation in a buffered salts medium. The ATP/mg plaque and ATP/colony-forming unit decreased by 50% during the 1st h of incubation at 37 °C, while viability remained relatively constant. For ATP/mg plaque, the coefficient of variation was least (33.2%) immediately after collection and dispersion and increased thereafter (to 42.6%). Therefore, ATP analysis shortly after plaque collection will provide the most sensitive and reproducible measure of viable plaque biomass

ISSN:0008-6568    

DOI:10.1159/000260844

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

This study, on 12 young adults, was designed to determine the relationship between the sucrose concentration (0–80%) in the mouth and the flow rates of both whole and parotid saliva. In addition, the peak flow rate of parotid saliva was determined and the time interval between sucrose ingestion and achievement of maximum flow rate (DELAY), since these parameters were identified as determinants of oral clearance of sugar in a recent theoretical study of that process (Caries Res. 17:321–334, 1983). The mean ( ± SD) value of DELAY was 6.5 ± 2.1 s, which was independent of sucrose concentration. The peak flow rate was maintained only for a few seconds and then declined to a level linearly related to the sucrose concentration. However, even with 80% sucrose, mean flow rates for parotid and whole saliva, over the initial 30 s of stimulation, were only 0.39 ± 0.10 ml/min/gland and 3.8 ± 0.51 ml/min, respectively, with peak parotid flow rates being about double the mean values. To promote oral sugar clearance, it is desirable that dietary sources of sucrose be consumed only in association with foodstuffs having strong stimulatory effects on saliva

ISSN:0008-6568    

DOI:10.1159/000260845

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

The rehardening of artificially softened human enamel by nine different saliva substitutes and four control solutions in vitro has been investigated by microhardness measurements. The saliva substitutes were all based on the same formula, containing mucins or carboxymethylcellulose (CMC) as the main macromolecules, and phosphate, calcium and fluoride as the main electrolytes, and sorbitol or xylitol. All the saliva substitutes had a rehardening potential. The largest reduction of the rehardening potential was observed after addition of high concentrations of CMC or mucins and the addition of sorbitol. The best rehardening properties were observed for low viscous mucin- or CMC-containing saliva substitutes with xylitol.

ISSN:0008-6568    

DOI:10.1159/000260846

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Innate calcium, phosphate, and fluoride were removed from gelatin gels by dialysis. Gels were reconstituted to 25% (w/v) gelatin to contain 75 mM lactic acid, 25 mM acetic acid, desired concentration of calcium, phosphate, and fluoride, all at pH 4.2. Human enamel surfaces, 0.15 cm2 each, were interfaced 96 days with 200 μl gel. Demineralization-remineralization were evaluated by calcium and phosphate analysis, hardness-like tests, and polarized-light microscopy. Fluoride (0.25 mM) alone in gels and with added calicum and phosphate enhanced remineralization and reduced enamel surface demineralization

ISSN:0008-6568    

DOI:10.1159/000260847

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

The present work was carried out to modify a self-gelling liquid composition for fluoride application to teeth so it would gel with reduced fluoride content. Past work had shown that quaternary ammonium compounds with carbon chain lengths in the C12 to C16 range or surface modifiers such as hydroxylamine-HCl in conjunction with surfactants facilitated gelation in systems of tetraethoxysilane and aqueous sodium fluoride solutions containing 1,900 ppm or more fluoride. A search was conducted among amines, imines and heterocyclic compounds for agents that would facilitate gelation in systems with lower fluoride concentrations. The findings were that imidazole-HCl in conjunction with a surfactant could effect gelation within minutes in systems with as little as 100 ppm fluoride and, further, that gelation of such systems was not affected by the presence of a series of disinfectants, antibiotics or hormones. Thus, it appears that the self-gelling system may be used as a vehicle for medicaments other than fluoride.

ISSN:0008-6568    

DOI:10.1159/000260848

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

The influence of particle size and tooth brush stiffness on abrasion of dentine was determined by means of a brushing machine, using 1,000, 2,000, 5,000, and 10,000 strokes and 200 g tooth brush load. Tooth pastes with two particle sizes were used: 7 and 15 μm diameter for the CaCO3 and 8 and 13 μm for Al(OH)3 abrasive systems. Abrasion was measured by a surface profilometer system and expressed in mean depth. The results show that (1) abrasion was always linearly correlated to the number of strokes; (2) nearly independent of the tooth paste system the abrasion is roughly 1.4 × more severe for the medium than for the soft brush; (3) the abrasion rates (average thickness removed per stroke) prooved to be significantly (p < 0.05) different for all four tooth paste systems, and (4) larger particles lead to higher abrasion rates for both abrasive syste

ISSN:0008-6568    

DOI:10.1159/000260849

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

The incorporation and retention of fluoride in exposed dentin surfaces following topical application of TiF4 (1.1 M F, pH 1.0) was compared to the effects of NaF (0.5 M F, pH 7.0) and two fluoride-containing varnishes. Ground dentin surfaces were prepared in anterior teeth of Five beagles. Each dog received a single application of one of the four fluoride agents; the fifth dog was left untreated. 3 weeks later the F, Ti and Ca contents in the experimental dentin surfaces were determined by electron microprobe analysis. The highest F concentrations were found after application of TiF4 and the two F-containing varnishes. The NaF-treated dentin surfaces showed lower F concentrations. In addition, F had permeated much more deeply in TiF4-treated and varnished dentin than in NaF-treated surfaces. A titanium-rich coating had remained on the dentin surface of these specimens. These preliminary results indicate that TiF4 may be an efficient anti-caries topical agent for application to dentin surfaces which have become exposed as a result of abrasion or root planing.

ISSN:0008-6568    

DOI:10.1159/000260850

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Three procedures for the analysis of fluoride (F) were evaluated. F was determined by means of: a F-specific electrode (A), a microanalytical technique involving a modification of a F-specific electrode (B), and gas chromatography (C). Approximately 2.5 mg enamel were obtained from each of 20 maxillary permanent molars, weighed accurately, and dissolved in 500 μl 2 M HClO4; 100 μl of this solution were diluted with 500 μl TISAB (1:1) containing 0.4 M NaOH. Of the diluted solution, 500 μl were used for the determination of F by means of A, 5 μl by means of B and 25 μl by means of C. The recovery of F added to standard F solutions was studied by means of B and C. Highly significant correlations among the enamel F concentrations were obtained with the three analytical techniques. The high recovery of F added to the standard F solutions by procedures B and C indicated that both these techniques are acc

ISSN:0008-6568    

DOI:10.1159/000260851

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Intraoral fluoride uptake produced by both systemic administration and topical rinsing was evaluated using two test regimens. Presoftened bovine enamel slabs were worn intraorally in a modified orthodontic appliance by two 23-year-old adults. The regimens consisted of: (a) a control in order to assess the residual activity of the fluoride ion in the mouth; (b) a 5-mg dose of fluoride administered in five 2.2-mg NaF-containing gelatin capsules which are swallowed, and (c) a fluoride mouthrinse containing 5 mg of fluoride in 1 liter of distilled water. The intraoral exposure of the enamel slabs for each regimen was 8 h. Measurable fluoride uptake by the enamel slabs was observed in all three regimens, with both treatment groups significantly different (p < 0.05) from the controls. At the 5 μm estimated depth from the surface of the enamel, the resulting fluoride levels (ppm) were (a) 288 ± 75, (b) 645 ± 97 and (c) 2,820 ±

ISSN:0008-6568    

DOI:10.1159/000260852

出版商:S. Karger AG    

年代:1985

数据来源: Karger