title: Renal fluoride excretion in children following topical application of fluoride varnish.
abstract: OBJECTIVE
  To demonstrate that the application of dental fluoride varnishes in children increases urinary fluoride  excretion.
  
  
  METHODS
  From a randomly assembled group of 42 children aged between 5 and 8 years,  residing in a community with non-fluoridated water, spot urinary samples were taken before the topical application of dental  fluoride varnish and 2 hours afterwards. In an age-matched control group of 16 children from the same community, who  received no treatment, samples were taken the same way. The urinary excretion of fluoride was analysed by determining  fluoride ion (F-) level and fluoride/creatinine (F/Cr) ratio in the urine.
  
  
  RESULTS
  In the study group, the average pre- and  post-treatment F/Cr ratios were 0.42 and 1.38 mg/g, respectively (p < .001). No significant changes were observed in the  control group, which received no treatment. The average 2 hours afterward F/Cr ratios were 0.29 and 0.27 respectively (p  = 0.426).
  
  
  CONCLUSIONS
  The topical application of dental fluoride varnish leads to a significant increase in urine F-,  which is attributable to the application of the product.
authors.affiliation: Department of Odontology, Faculty of Biomedical Sciences, European University of Madrid, Spain.
authors.forename: F
authors.initials: F
authors.lastname: García-Hoyos
authors.forename: E
authors.initials: E
authors.lastname: Barbería
authors.forename: P
authors.initials: P
authors.lastname: García-Camba
authors.forename: M
authors.initials: M
authors.lastname: Varela
mesh_terms: D002327:Cariostatic Agents / Q000032:analysis* / Q000627:therapeutic use; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D002851:Chromatography, High Pressure Liquid; D003404:Creatinine / Q000652:urine; D005260:Female; D005459:Fluorides / Q000652:urine*; D005460:Fluorides, Topical / Q000627:therapeutic use*; D005500:Follow-Up Studies; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007668:Kidney / Q000378:metabolism*; D008297:Male; D011199:Potentiometry; D012969:Sodium Fluoride / Q000627:therapeutic use
chemical_list: D002327:Cariostatic Agents; D005460:Fluorides, Topical; C023807:sodium fluoride topical preparation; D012969:Sodium Fluoride; D003404:Creatinine; D005459:Fluorides