ISSN:0008-6568    

DOI:10.1159/000260722

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

The fluorophosphates, discovered in Germany in the 1920s, were selected for study and possible commercialization by the Ozark Chemical Co. of Tulsa, Okla., in the 1940s. In 1950, sodium monofluorophosphate (MFP) was reported to have anticaries activity and to be of low toxicity. These characteristics plus the relatively high solubility of the calcium salt led to worldwide adoption of MFP as a dentifrice additive. The possibility exists that MFP may assume even greater importance in preparations for the prevention and treatment of osteoporosis.

ISSN:0008-6568    

DOI:10.1159/000260723

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

The commonest method for fluoride analysis is the fluorideion-specific electrode. Other methods for fluoride analysis include volumetric, colorimetric, gas chromatographic, ion chromatography and nondestructive nuclear methods. The monofluorophosphate (MFP) ion is analyzed directly by ion exchange, ion chromatography or paper chromatography. The MFP ion is also determined by analysis before and after hydrolysis of the fluoride ion. Only a limited number of reports on 18F- and 32P-labeled MFP have been made.

ISSN:0008-6568    

DOI:10.1159/000260724

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

The aim of this study was to compare the rate of etching and the surface roughness of HClO4 etched enamel surfaces. The average thickness of the enamel layer removed is a linear function of the total etching period (except for very short periods). The rate of etching (β) in μm s––1 with HCIO4 is strongly influenced by acid strength and stirring rate during etching; it is ∼ 0.02, 0.06, 0.18 and 0.74 μm s––1 for 0.02, 0.1, 0.5 and 2.0 M HCIO4, respectively, β is a linear function of the acid strength. Scanning electron microscopy (SEM) pictures of the specimens show that acid strength, etching time and chemical composition of the enamel are most likely important factors determining surface morphology of etched enamel. A lower acid concentration gives a sharper etch; increasing acid strength causes increasing surf

ISSN:0008-6568    

DOI:10.1159/000260644

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

Monofluorophosphate (MFP) can be synthesized in vitro by the transfer of a phosphoryl group from ATP to F-, catalyzed by pyruvate kinase, or by the autocatalytic transfer of a phosphoryl group from the enzyme phosphoglucomutase. There is, however, no evidence that MFP is a normal intermediate in cell metabolism. MFP can be degraded by both alkaline and acid phosphatases, and the mechanism is probably similar to the hydrolysis or transfer of phosphoryl groups from other phosphatase substrates. MFP competitively inhibits pyruvate kinase and alkaline phosphatase, and irreversibly inhibits phosphorylase phosphatase. The possibility that impurities or hydrolysis products are responsible for reported effects makes the interpretation of many inhibition studies difficult. The widespread therapeutic use of MFP presents a strong case for a more detailed study of its metabolism.

ISSN:0008-6568    

DOI:10.1159/000260726

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

This paper describes analytical methods for the determination of calcium, phosphate and fluoride in successive layers of enamel removed from rat and human teeth by acid etching. These methods include: (i) simple, sensitive spectrophotometric methods for the determination of calcium and phosphate; (ii) an easily constructed miniature fluoride electrode, and (iii) an improved electrode adapter that permits one fluoride electrode to measure numerous microsamples very rapidly. The high sensitivity and simplicity of the analytical techniques described allows many types of microsamples of interest in dental research to be analyzed with an accuracy and speed heretofore attainable only with much larger samples.

ISSN:0008-6568    

DOI:10.1159/000260645

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

Prototype anion-exchanging resins were used to treat artificial carious lesion; The resins penetrate into lesion porosity, harden, and release either F or Cl ions. After second demineralization, various histological features of the lesions were measured. I progression of untreated lesions, surface zones (SZ) decreased by 75% and lesion bodie increased by 86%, while in resin-treated lesions the SZ remained essentially constant ant lesion bodies increased by only 52%. Dark zones (DZ) of F resin-treated lesions wer significantly larger than the DZ of Cl resin-treated, untreated, and initial lesions. After initiation of lesions in sound enamel, the SZ was essentially the same for botl treated and untreated enamel but slightly larger lesion bodies developed in the treate( enamel. After demineralization, the DZ of F resin-treated enamel were significantly larger than in Cl resin-treated or untreated enamel. In a separate experiment the rate of phosphate release from demineralized enamel into i pH 4.5 buffer was decreased by 85% by a F resin treatment and by 41% by a Cl resin treatment. In summary, both resins act as a barrier to demineralization and the fluoride-releasing resin appears to promote remineralization during acid attack.

ISSN:0008-6568    

DOI:10.1159/000260646

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

The toxic effects of monofluorophosphate (MFP) are attributable to the fluoride ion released by the in vivo hydrolysis of the parent compound. The MFP ion appears to play no role. The acute toxicity of MFP is somewhat less than that of NaF, due to the lesser availability of fluoride in the short term from MFP. In the long term, MFP produces virtually the same picture of renal effects and skeletal storage of fluoride as does NaF.

ISSN:0008-6568    

DOI:10.1159/000260727

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

The in vitro fluoride acquired by human enamel after application of APF, Duraphat (a resin varnish) and Fluor Protector (a polyurethane varnish), respectively, and subjected to various procedures was determined. Fluoride acquisition was the greatest in teeth treated with Duraphat and Fluor Protector and the least in APF-treated teeth. Fluoride uptake and distribution were not increased by extending the contact time between the topical fluoride agents and enamel from 4 to 24 h. Reapplication of the topical fluoride agents did not increase fluoride acquisition. Fluorapatite was the predominant reaction product with Duraphat and Fluor Protector and alkali-soluble fluorides with APF application.

ISSN:0008-6568    

DOI:10.1159/000260647

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

Ingested monofluorophosphate (MFP) is hydrolyzed by phosphatases mainly in the lumen and wall of the small intestine. MFP hydrolysis is insignificant in the saliva and the stomach and absorption is greatest in the small intestine, mainly or entirely as F ions. Liver tissue also rapidly hydrolyzes MFP, and MFP ions have not been found parenterally. The post-absorption physiology of MFP therefore appears to be identical with that of NaF, which is briefly summarized. However, the absorption peaks of F in blood and other body fluids and tissues occur earlier and are higher after NaF ingestion, unless F is bound by Ca ions in the digestive tract. Ca ions have a comparatively small effect on F absorption from MFP, and complex-bound Ca has practically no effect.

ISSN:0008-6568    

DOI:10.1159/000260728

出版商:S. Karger AG    

年代:1983

数据来源: Karger