The composition of the aqueous phase in human dental plaque

Tatevossian, A.; Gould, Catherine

doi:10.1016/0003-9969(76)90055-8

Cited by 106 publications

(58 citation statements)

References 28 publications

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“…A micro transfer pipette [Vogel et al, 1990] was used to remove as much water as possible after the water extraction and to dilute the small volumes employed in the no-rinse samples with TISAB. Because of the low volumes employed in these latter samples, a slight correction to the extraction volume was made by assuming that plaque has a mass fraction of 35% fluid [Tatevossian and Gould, 1976]. Aliquots of the TISAB-diluted saliva and whole-plaque extracts were analyzed using an oil-covered inverted fluoride electrode apparatus [Vogel et al, 1997].…”

Section: Analysis Methodsmentioning

confidence: 99%

Effect of a Water Rinse on ‘Labile’ Fluoride and Other Ions in Plaque and Saliva before and after Conventional and Experimental Fluoride Rinses

et al. 2001

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Labile reservoirs are important in maintaining ion concentrations in oral fluids, especially after a fluoride dentifrice application, where a persistent increase in fluid fluoride can mitigate or reverse caries progression. In this study, the effect of experimental and conventional fluoride rinses on the in vitro and in vivo water–induced release of fluoride, calcium, phosphate, acetate and hydrogen ions from oral reservoirs was examined. At the start of each experiment, 13 subjects rinsed either with a conventional 228–ppm fluoride NaF rinse, a 228–ppm fluoride controlled–release rinse (CR rinse) or received no rinse. Sixty minutes later upper and lower molar plaque samples and 1–min saliva samples were collected. The subjects then rinsed with deionized water for 1 min, and 7 min later, a second set of samples was collected (in vivo study). Plaque fluid and clarified saliva were then recovered from samples by centrifugation, and the remaining plaque mass was sequentially extracted with water and acid to measure the water–extracted and total whole–plaque fluoride (in vitro study). All the samples were analyzed using microtechniques for pH, free calcium, phosphate, organic acids (plaque fluid) and fluoride (plaque fluid, centrifuged saliva and plaque extracts). Results showed that in vivo water rinsing decreased acetate and phosphate in plaque fluid, and fluoride in plaque fluid and saliva, but had no effect on plaque fluid pH. In vivo water rinsing, however, increased plaque fluid free calcium, apparently due to water–induced loss of calcium–binding ions. Water– or fluoride–rinse–induced changes in plaque fluid concentration were greater at the lower molar site, suggesting that rinse pooling may influence ion distribution. Before the water rinse, plaque fluid, saliva and whole–plaque total fluoride values were 1.7, 2 and 4 times higher after the CR rinse compared to the NaF rinse. Furthermore, the CR rinse deposited approximately 11 times more water–extracted fluoride compared to the NaF rinse, suggesting a ‘more efficient’ precipitation of ‘labile’ or ‘loosely bound fluoride’. The results presented here, and in previous studies, suggest the possibility of formulating effective fluoride dentifrices with a lower fluoride content than is currently in use.

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Section: Analysis Methodsmentioning

confidence: 99%

Effect of a Water Rinse on ‘Labile’ Fluoride and Other Ions in Plaque and Saliva before and after Conventional and Experimental Fluoride Rinses

et al. 2001

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“…It should be noted in regard to this procedure that (1) the removal of the small volume of plaque fluid does not significantly reduce the fluoride in the plaque residue (i.e. fluoride in the plaque fluid residue is thus nearly equal to whole plaque fluoride); (2) because of the low volumes used in these extractions, a slight correction to the extraction volume was made by assuming that plaque fluid is a volume fraction 35% of the plaque [Tatevossian and Gould, 1976], and (3) the room temperature hydrolysis of NaMFP in 0.1 mol/l HClO 4 is slow (no measurable release of F was found from the 20-min acidification of a 100 µmol/l NaMFP solution). However, this acid is strong enough to recover nearly all the fluoride (samples re-extracted for 4 h with 1 mol/l HClO 4 recovered only about an additional mass fraction of 15% fluoride).…”

Section: Collection and Analysis Of Samplesmentioning

confidence: 99%

Fluoride in Plaque Fluid, Plaque, and Saliva Measured for 2 hours after a Sodium Fluoride Monofluorophosphate Rinse

Vogel

Y²,

Chow³

et al. 2000

Caries Res

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Sodium monofluorophosphate (NaMFP) and sodium fluoride (NaF) are the two most common sources of fluoride used in currently marketed fluoride dentifrices. The purpose of this study was to investigate the effect of mouth rinses containing NaF or NaMFP on the concentrations of fluoride, or the MFP ion, in saliva, whole plaque, and plaque fluid. Twelve subjects abstained from tooth brushing for 48 h, fasted overnight, and then rinsed 1 min with 12 mmol/l (228 ppm [μg/g] F) NaF or NaMFP in the morning. Before the rinse and at 30, 60 and 120 min afterwards, upper and lower molar and premolar plaque samples and whole saliva samples were collected. Aliquots of plaque fluid and centrifuged saliva were obtained from these samples, and the whole plaque residue acid extracted. The F and MFP concentrations were then measured in these samples using ultramicro methods. For both rinses, a higher concentration of plaque fluid fluoride was found at lower molar sites while the reverse was true for the whole plaque fluoride. Furthermore, for both rinses, plaque fluid, whole plaque, but not salivary, fluoride concentrations were above baseline at 120 min. Following the NaMFP rinse, a substantial amount of unhydrolyzed MFP was found in plaque fluid and saliva. Although there was a very large range in these measurements, fluoride in plaque fluid (excluding fluoride in unhydrolyzed MFP) and whole plaque were significantly (p<0.05) greater after the NaF rinse at all time periods. In saliva, the NaF rinse produced a statistically significant greater salivary fluoride (excluding fluoride in unhydrolyzed MFP) only at 60 min. The lack of a clear correlation between these measurements and clinical studies suggest a novel mechanism may enhance the effectiveness of NaMFP dentifrices.

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“…Those researchers showed that the presence of potassium ions was required for transport and that, in environments of pH 6.0 or below, the activity of the H ϩ -ATPase system was required (38,45). Potassium ions are the main cations in plaque (50), and potassium uptake is associated with intracellular pH homeostasis in S. mutans (24,35). In addition, expression of several genes involved in the glutamate synthesis pathway (icd, citZ, and acn) are downregulated under low pH (10), suggesting a link between glutamate metabolism, potassium levels, and aciduricity in S. mutans.…”

mentioning

confidence: 99%

Characterization of a Glutamate Transporter Operon, glnQHMP , in Streptococcus mutans and Its Role in Acid Tolerance

et al. 2010

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Glutamate contributes to the acid tolerance response (ATR) of many Gram-negative and Gram-positive bacteria, but its role in the ATR of the oral bacterium Streptococcus mutans is unknown. This study describes the discovery and characterization of a glutamate transporter operon designated glnQHMP (Smu.1519 to Smu.1522) and investigates its potential role in acid tolerance. Deletion of glnQHMP resulted in a 95% reduction in transport of radiolabeled glutamate compared to the wild-type UA159 strain. The addition of glutamate to metabolizing UA159 cells resulted in an increased production of acidic end products, whereas the glnQHMP mutant produced less lactic acid than UA159, suggesting a link between glutamate metabolism and acid production and possible acid tolerance. To investigate this possibility, we conducted a microarray analysis with glutamate and under pH 5.5 and pH 7.5 conditions which showed that expression of the glnQHMP operon was downregulated by both glutamate and mild acid. We also measured the growth kinetics of UA159 and its glnQHMP-negative derivative at pH 5.5 and found that the mutant doubled at a much slower rate than the parent strain but survived at pH 3.5 significantly better than the wild type. Taken together, these findings support the involvement of the glutamate transporter operon glnQHMP in the acid tolerance response in S. mutans.

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The composition of the aqueous phase in human dental plaque

Cited by 106 publications

References 28 publications

Effect of a Water Rinse on ‘Labile’ Fluoride and Other Ions in Plaque and Saliva before and after Conventional and Experimental Fluoride Rinses

Effect of a Water Rinse on ‘Labile’ Fluoride and Other Ions in Plaque and Saliva before and after Conventional and Experimental Fluoride Rinses

Fluoride in Plaque Fluid, Plaque, and Saliva Measured for 2 hours after a Sodium Fluoride Monofluorophosphate Rinse

Characterization of a Glutamate Transporter Operon, glnQHMP , in Streptococcus mutans and Its Role in Acid Tolerance

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