Comparison of the in vivo Effect of a 0 and 1,500 ppmF MFP Toothpaste on Fluoride Uptake, Acid Resistance and Lesion Remineralization

1986 ◽  
Vol 20 (3) ◽  
pp. 193-201 ◽  
Author(s):  
J.M. ten Cate ◽  
H.E. Rempt
Keyword(s):  
Acid Resistance ◽  
Fluoride Uptake

Fluoride uptake in human dentine from glass-ionomer cement in vivo

1993 ◽  
Vol 38 (12) ◽  
pp. 1093-1098 ◽  
Author(s):  
M. Murai ◽  
M. Ikeda ◽  
T. Yanagihara ◽  
G. Hara ◽  
K. Kato ◽  
...  
Keyword(s):  
Glass Ionomer Cement ◽  
Glass Ionomer ◽  
Fluoride Uptake ◽  
Human Dentine ◽  
Ionomer Cement

scholarly journals Differences in Enzymatic Properties Allow SodCI but Not SodCII To Contribute to Virulence in Salmonella enterica Serovar Typhimurium Strain 14028

2004 ◽  
Vol 186 (16) ◽  
pp. 5230-5238 ◽  
Author(s):  
Radha Krishnakumar ◽  
Maureen Craig ◽  
James A. Imlay ◽  
James M. Slauch
Keyword(s):  
Salmonella Enterica ◽  
Osmotic Shock ◽  
Acid Resistance ◽  
Noncovalent Interaction ◽  
Open Reading Frames ◽  
Striking Difference ◽  
Significant Difference ◽  
Serovar Typhimurium

ABSTRACT Salmonella enterica serovar Typhimurium produces two Cu/Zn cofactored periplasmic superoxide dismutases, SodCI and SodCII. While mutations in sodCI attenuate virulence eightfold, loss of SodCII does not confer a virulence phenotype, nor does it enhance the defect observed in a sodCI background. Despite this in vivo phenotype, SodCI and SodCII are expressed at similar levels in vitro during the stationary phase of growth. By exchanging the open reading frames of sodCI and sodCII, we found that SodCI contributes to virulence when placed under the control of the sodCII promoter. In contrast, SodCII does not contribute to virulence even when expressed from the sodCI promoter. Thus, the disparity in virulence phenotypes is due primarily to some physical difference between the two enzymes. In an attempt to identify the unique property of SodCI, we have tested factors that might affect enzyme activity inside a phagosome. We found no significant difference between SodCI and SodCII in their resistance to acid, resistance to hydrogen peroxide, or ability to obtain copper in a copper-limiting environment. Both enzymes are synthesized as apoenzymes in the absence of copper and can be fully remetallated when copper is added. The one striking difference that we noted is that, whereas SodCII is released normally by an osmotic shock, SodCI is “tethered” within the periplasm by an apparently noncovalent interaction. We propose that this novel property of SodCI is crucial to its ability to contribute to virulence in serovar Typhimurium.

Mode of Action of Fluoride: Application of New Techniques and Test Methods to the Examination of the Mechanism of Action of Topical Fluoride

1994 ◽  
Vol 8 (2) ◽  
pp. 166-174 ◽  
Author(s):  
D.J. White ◽  
D.G.A. Nelson ◽  
R.V. Faller
Keyword(s):  
Acid Resistance ◽  
Test Methods ◽  
Magic Angle Spinning ◽  
Treatment Modalities ◽  
Magic Angle ◽  
Reaction Products ◽  
In Situ Experiments ◽  
Ph Cycling

Modern techniques in dental research continue to assist in the study of the mode of (anticaries) action of topical fluorides. The Plaque Glycolysis and Regrowth Model (PGRM) facilitates the standardized assessments of antimicrobial effects on plaque following use of test formulations in vivo without complications arising from coincident mineral reactivity. In vivo plaque glycolysis testing demonstrates that topically applied fluoride, at conventional levels found in dentifrices, has only modest effects on the metabolic (acid-producing) activity of dental plaque. Any 'plaque' contribution to fluoride efficacy must come from more subtle effects on plaque acidogenicity than those measured in PGRM. The 19-F MAS NMR (Magic Angle Spinning Nuclear Magnetic Resonance) technique provides unambiguous measures of the reaction products of F-enamel interactions. Studies have revealed a new 'reaction product' of fluoride-enamel interactions-designated as Non-Specifically-Adsorbed Fluoride, NSAF. This species, along with FAP (fluoroapatite), FHAP (fluorohydroxyapatite), and CaF2 (calcium fluoride), contributes to the remineralization/ demineralization benefits of fluoride. pH cycling and in situ denture chip studies permit quantitative assessments to be made of the relative benefits of fluoride in promoting remineralization and in inhibiting demineralization. Results from pH cycling/ in situ experiments are strongly supportive of Koulourides' 'Acquired Acid Resistance' concept, describing fluoride's decay-preventive effects. The continued application of new analytical/physical techniques and testing regimens to the study of fluoride anticaries mechanisms may lead to the development of improved fluoride agents/treatment modalities for the prevention of dental caries.

Fluoride release from an orthodontic glass ionomer adhesive in vitro and enamel fluoride uptake in vivo

2010 ◽  
Vol 137 (4) ◽  
pp. 458.e1-458.e8 ◽  
Author(s):  
Evangelia Chatzistavrou ◽  
Theodore Eliades ◽  
Spiros Zinelis ◽  
Athanasios E. Athanasiou ◽  
George Eliades
Keyword(s):  
Fluoride Release ◽  
Glass Ionomer ◽  
Fluoride Uptake

Survival of Bacillus cereus Vegetative Cells and Spores during In Vitro Simulation of Gastric Passage

2012 ◽  
Vol 75 (4) ◽  
pp. 690-694 ◽  
Author(s):  
SIELE CEUPPENS ◽  
MIEKE UYTTENDAELE ◽  
KATRIEN DRIESKENS ◽  
ANDREJA RAJKOVIC ◽  
NICO BOON ◽  
...  
Keyword(s):  
Bacillus Cereus ◽  
Acid Resistance ◽  
In Vitro Experiments ◽  
Vegetative Cells ◽  
Ph Values ◽  
Constant Ph ◽  
In Vitro Simulation ◽  
Ph Range

The enteric pathogen Bacillus cereus must survive gastric passage in order to cause diarrhea by enterotoxin production in the small intestine. The acid resistance and the survival after gastric passage were assessed by in vitro experiments with acidified growth medium and gastric simulation medium with B. cereus NVH 1230-88 vegetative cells and spores. First, batch incubations at constant pH values for 4 h, which represented different physiological states of the stomach, showed that spores were resistant to any gastric condition in the pH range of 2.0 to 5.0, while vegetative cells were rapidly inactivated at pH values of ≤4.0. Second, a dynamic in vitro gastric experiment was conducted that simulated the continuously changing in vivo conditions due to digestion dynamics by gradually decreasing the pH from 5.0 to 2.0 and fractional emptying of the stomach 30 to 180 min from the start of the experiment. All of the B. cereus spores and 14% (±9%) of the vegetative cells survived the dynamic simulation of gastric passage.

Fluoride uptake and acid resistance of enamel irradiated with Er:YAG laser

2007 ◽  
Vol 23 (2) ◽  
pp. 141-147 ◽  
Author(s):  
Flávia M. Bevilácqua ◽  
Denise Maria Zezell ◽  
Romeu Magnani ◽  
Patricia A. da Ana ◽  
Carlos de Paula Eduardo
Keyword(s):  
Er:Yag Laser ◽  
Acid Resistance ◽  
Fluoride Uptake

Enamel Fluoride Uptake and Acid Resistance in Subjects with High and Low Experimental Cariogenicity

1984 ◽  
Vol 63 (2) ◽  
pp. 133-136 ◽  
Author(s):  
C.A. Ostrom ◽  
T. Koulourides ◽  
D.H. Retief ◽  
E.L. Bradley
Keyword(s):  
Acid Resistance ◽  
Fluoride Uptake

Enamel Microsampling Technique for Assessing Fluoride Uptake from Topical Fluoride Treatments In Vitro

1973 ◽  
Vol 52 (6) ◽  
pp. 1268-1272 ◽  
Author(s):  
Stephen H.Y. Wei
Keyword(s):  
Electric Motor ◽  
Pressure Gauge ◽  
Fluoride Uptake ◽  
Topical Fluoride

A handpiece driven by an electric motor and with a pressure gauge and a preset timer was found to be a satisfactory tool for the in vitro and in vivo microsampling of enamel fluoride in the first 1 to 2 micrometer layer of enamel.

Sign in / Sign up

Export Citation Format

Share Document