Salivary concentrations of urea released from a chewing gum containing urea and how these affect the urea content of gel-stabilized plaques and their pH after exposure to sucrose.
The objectives were to: (1) determine the salivary concentrations of urea during 20 min chewing of a sugar-free gum containing 30 mg of urea; (2) measure the degree to which this urea would diffuse into a gel-stabilized plaque; (3) study the effect of the urea on the fall and subsequent rise in pH (...
| Publicado en: | Caries Research Vol. 35; no. 5; pp. 344 - 354 |
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| Autores principales: | , , , |
| Formato: | research tables/charts Journal Article |
| Publicado: |
Karger AG
Sep/Oct2001
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| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=ccm&AN=106925431&site=ehost-live header: @attributes: shortDbName: ccm uiTerm: 106925431 longDbName: CINAHL Complete uiTag: AN controlInfo: bkinfo: dissinfo: jinfo: jid: 00086568 DEU jtl: Caries Research issn: 00086568 maglogo: N pubinfo: dt: Sep/Oct2001 vid: 35 iid: 5 pid: 2485 pub: Karger AG artinfo: ui: 106925431 106925431 NLM11641570 2002056612 10.1159/000047473 NLM11641570 106925431 ppf: 344 ppct: 10 formats: tig: atl: Salivary concentrations of urea released from a chewing gum containing urea and how these affect the urea content of gel-stabilized plaques and their pH after exposure to sucrose. aug: au: Dawes C Dibdin GH Dawes, C Dibdin, G H affil: Department of Oral Biology, University of Manitoba, Winnipeg, Man., Canada sug: subj: Saliva Analysis Urea Analysis Chewing Gum Analysis Dental Plaque Cariogenic Agents Pharmacodynamics Sucrose Pharmacodynamics Funding Source Hydrogen-Ion Concentration Streptococcus Computer Simulation Algorithms Male Female Adult Middle Age Models, Biological Time Factors Urease Metabolism Evaluation Research Specimen Handling Descriptive Statistics Human Adult: 19-44 years Middle Aged: 45-64 years Male Female ab: The objectives were to: (1) determine the salivary concentrations of urea during 20 min chewing of a sugar-free gum containing 30 mg of urea; (2) measure the degree to which this urea would diffuse into a gel-stabilized plaque; (3) study the effect of the urea on the fall and subsequent rise in pH (Stephan curve) on exposure to 10% sucrose for 1 min; (4) model the measurements 2 and 3 mathematically. In point 1, the salivary urea concentration of the 12 subjects peaked at 47 mmol/l in the first 2 min of gum chewing, falling within 15 min to the unstimulated salivary concentration of 3.4 mmol/l. Recovery of urea from the saliva averaged 81.5%. 'Plaques' of 1% agarose or 67% dead bacteria in agarose accumulated urea from the saliva roughly as expected, whereas those plaques containing 8% live and 59% dead Streptococcus vestibularis showed negligible accumulation. Computer modelling showed this difference to be due to urease of live bacteria breaking down the urea as rapidly as it entered the plaque. Simulation of the effect of gum chewing subsequent to initiation of a Stephan curve in the latter type of plaque showed a rapid rise in pH but then a fall again on return to unstimulated conditions. This fall had not been seen in previous studies, with Streptococcus oralis, nor was it predicted by the computer modelling. Neither experimental simulation nor computer modelling suggested that chewing urea-containing gum before exposure to sucrose would have any effect on a subsequent Stephan curve. Thus chewing gum is only likely to inhibit caries when it is chewed after consumption of fermentable carbohydrate, rather than before. pubtype: Academic Journal doctype: research tables/charts Journal Article ougenre: Article language: English refInfo: holdings: @attributes: islocal: N |
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