摘要:

Mixed salivary proteins, obtained by fractional ultrafiltration of centrifuged human saliva were utilized by Streptococcus mutans or Streptococcus sanguis as sources of amino acids for growth, but these proteins supported only limited growth of Streptococcus salivarius or Streptococcus mitior. Comparative analyses of the isoelectric focused protein patterns before and following growth with these oral streptococci revealed a distinct pattern of salivary proteins which were susceptible to alteration by each species. Proteins with isoelectric points of 4.90, 5.33, 5.50, 5.58, 5.72, 5.80, 6.00 and 6.10 usually susceptible to alteration by S. mutans were seldom affected by the other oral streptococci. Growth attained by the oral streptococci in defined medium containing fractions of partially purified proteins was related to the presence or absence of proteins specifically altered by the organisms.

ISSN:0008-6568    

DOI:10.1159/000260399

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

Identification and indexing of lattice planes through high-resolution transmission electron microscopy provided precise measurements of intertubular crystals of arrested caries in dentine compared to sound dentine. In arrested caries, mean crystal width was 310 Å (SD 44) with a range from 200 to 400 Å. Mean thickness was 86 A (SD 19.3) with a range from 57 to 130 Å. In sound dentine, mean width was not very different at 296 Å (SD 39) with a similar range from 200 to 400Å. Mean thickness was lower: 31.6 Å (SD 5.4) with a range from 24 to 41 Å. A growing process due to thickening of the crystallites was pointed out. The coexistence of whitlockite and apatite within the large crystals of intratubular dentine in arrested caries was shown through high-resolution electron microscopy and micro-electron diffraction. Two stages of arrested caries could be found at the crystal level: firstly, a precipitate of the material dissolved at the very beginning of the carious process, and secondly, remineralization of decalcified dentine by growth of residual crystals (intertubular dentine) and by a maturating process of whitlockite towards apatite (intratubular cry

ISSN:0008-6568    

DOI:10.1159/000260400

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

Doses of strontium were given pre-eruptively to rats at 0.0, 2.5, 5.0 and 10.0 μg Sr/10 g body weight, with or without fluoride at 1.0 μg/l0 g body weight by esophageal intubation. In a second experiment strontium at concentrations of 0, 50, 100 and 150 mg Sr/l, with and without fluoride at 10 mg/l, were given via the drinking water post-eruptively. Caries scores were made for buccolingual, morsal, sulcal und proximal lesions in all rats. Slight reductions in buccolingual caries scores were seen in rats given 5.0 μg Sr/10 g body weight pre-eruptively. Rats given post-eruptive doses of strontium only showed marked reductions in buccolingual scores with 50 mg Sr/l, and 10 mg F/l. No effect was seen on morsal, sulcal or proximal caries scores for any of the treatment regimens. The greatest reductions in buccolingual caries scores were found when a combination of 50 mg Sr/l and 10 mg F/l was given post-eruptive

ISSN:0008-6568    

DOI:10.1159/000260401

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

Fluoride concentrations in the surface enamel of extracted incisors of adults were determined by prompt activation by proton bombardment. The teeth were then submitted to 4 min of topical fluoride treatments (commercial gels and solutions), and fluoride enrichments were measured after a short rinsing. The non-destructivity of the technique allowed to use the same area of the tooth before and after treatment. The highest amounts of fluoride were deposited in enamel treated with an amine fluoride solution (10,545 ppm). Good results were obtained with APF gels (2,200 ppm), whereas MFP gel gave a very low enrichment (243 ppm). Kinetic studies allowed to follow the rate of fluoride fixation which appears to vary according to a logarithmic scale.

ISSN:0008-6568    

DOI:10.1159/000260402

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

The adsorption of an organic high molecular polyphosphonate on bovine enamel and synthetic hydroxyapatite has been studied. Concentration and particle size of the solids and also pH and concentration of the phosphonate solution are important parameters for the amount of adsorbed polyphosphonate. During adsorption of the polyphosphonate, phosphate ions are released in solution. This observation correlates with the results of adsorption experiments in which low molecular diphosphonates were used. Adsorption kinetics seem to obey Langmuirs equation. The affinity constants and the binding capacities are calculated.

ISSN:0008-6568    

DOI:10.1159/000260403

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

Surface enamel was analyzed for strontium and fluoride on 439 teeth collected from Ohio and Wisconsin, USA. Mean concentrations were 366.4 μg Sr/g and 1,169.6 μg F/g. A significant, but weak correlation between fluoride concentration and caries as DMFT (r = ––0.16) was found, and also between strontium and fluoride concentrations (r = 0.48). No correlation of strontium in surface enamel and caries was

ISSN:0008-6568    

DOI:10.1159/000260404

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

If it is true that small children chronically swallow toothpaste while brushing their teeth, the possibility exists that the use of a fluoride toothpaste during infancy might result in the ingestion of sufficient F to cause mottling in their permanent teeth. In order to test this hypothesis, the infant siblings of children participating in the clinical trial of a dentifrice containing 2% sodium monofluorophosphate were examined 6–8 years afterwards, following the eruption of their permanent teeth. No hypoplasia or mottling were found which might be attributed to the ingestion of undesirable amounts of monofluorophosphate toothpast

ISSN:0008-6568    

DOI:10.1159/000260405

出版商:S. Karger AG    

年代:1979

数据来源: Karger

ISSN:0008-6568    

DOI:10.1159/000260406

出版商:S. Karger AG    

年代:1979

数据来源: Karger