title: Fluoride Varnishes--Is There a Correlation Between Fluoride Release and Deposition on Enamel?
abstract: OBJECTIVE
  Fluoride uptake of enamel after application of fluoride varnishes was compared with fluoride release into artificial saliva. The hypothesis was that fluoride uptake is higher for products exhibiting faster fluoride release.
  
  
  METHODS
  Fluoride varnishes, i.e. Fluor Protector S, Duraphat, MI Varnish, Clinpro White Varnish, Profluorid Varnish and Enamel Pro Varnish were applied on bovine enamel specimens. Subsequently, specimens were incubated in artificial saliva. After removal of the varnishes, surface bound fluoride was extracted with potassium hydroxide and measured with an ion-selective electrode. Structurally bound fluoride was etched from the same specimens with perchloric acid. Fluoride release of varnish films into artificial saliva was measured for comparison.
  
  
  RESULTS
  After 4 h in artificial saliva, the highest total enamel fluoride uptake of 47.9 μg F·cm-² was found with Fluor Protector S, followed by Enamel Pro Varnish with 22.1 μg F·cm-². The other products ranged between 12-16 μg F·cm-². This was several times higher than the negative control. Fluoride uptake did not correlate with release into artificial saliva. During the first 4 h, Duraphat released the lowest and MI Varnish the highest amount of fluoride with 7.7 and 249 μg F·cm-², respectively. The fluoride uptake of these two products was not statistically different.
  
  
  CONCLUSIONS
  Enamel fluoride uptake cannot be predicted from the fluoride release rate of a product. Hence, based on the results of this study, fluoride release into artificial saliva is no measure for the efficacy of a fluoride varnish.
authors.forename: Carlo
authors.initials: C
authors.lastname: Bolis
authors.forename: Gian Peider
authors.initials: GP
authors.lastname: Härtli
authors.forename: Urs
authors.initials: U
authors.lastname: Lendenmann
mesh_terms: D000818:Animals; D002130:Calcium Phosphates / Q000737:chemistry / Q000493:pharmacokinetics*; D002327:Cariostatic Agents / Q000737:chemistry / Q000493:pharmacokinetics*; D002417:Cattle; D003743:Dental Enamel / Q000378:metabolism*; D004058:Diffusion; D004338:Drug Combinations; D005460:Fluorides, Topical / Q000737:chemistry / Q000493:pharmacokinetics*; D017736:Ion-Selective Electrodes; D011140:Polyurethanes / Q000737:chemistry / Q000493:pharmacokinetics; D012464:Saliva, Artificial / Q000493:pharmacokinetics; D012821:Silanes / Q000737:chemistry / Q000493:pharmacokinetics; D012969:Sodium Fluoride / Q000737:chemistry / Q000493:pharmacokinetics*; D013997:Time Factors
chemical_list: D002130:Calcium Phosphates; D002327:Cariostatic Agents; D004338:Drug Combinations; C000612969:Enamel Pro Varnish; D005460:Fluorides, Topical; D011140:Polyurethanes; D012464:Saliva, Artificial; D012821:Silanes; C023807:sodium fluoride topical preparation; C022599:Fluor Protector; D012969:Sodium Fluoride