title: Fluoride release from fluoride varnishes under acidic conditions.
abstract: OBJECTIVE
  The aim was to investigate the in vitro fluoride release from fluoride varnishes under acidic conditions.
  
  
  METHODS
  Poly(methyl methacrylate) blocks (Perspex, n=3 per group) were painted with 80 ± 5 mg fluoride varnish (n=10) and placed into artificial saliva for 30 min. Then, blocks were placed into either 1% citric acid (pH 2.27) or 0.3% citric acid (pH 3.75) solutions (n=3 per solution and varnish) for 30 min with the solutions being replaced every 5 min. Saliva and acid solutions were analyzed for fluoride content. Data were analyzed using three-way ANOVA (varnish, solution, time).
  
  
  RESULTS
  The three-way interaction was significant (p>0.0001). Fluoride release and release patterns varied considerably between varnishes. Fluoride release in saliva varied by a factor of more than 10 between varnishes. Some varnishes (CavityShield, Nupro, ProFluorid, Vanish) showed higher fluoride release in saliva than during the first 5 min of acid exposure, whereas other varnishes (Acclean, Enamel-Pro, MI Varnish, Vella) showed the opposite behavior. There was little difference between acidic solutions.
  
  
  CONCLUSIONS
  Fluoride release from fluoride varnishes varies considerably and also depends on the dissolution medium. Bearing in mind the limitations of laboratory research, the consumption of acidic drinks after fluoride varnish application should be avoided to optimize the benefit/risk ratio.
authors: Department of Preventive and Community Dentistry, Oral Health Research Institute, Indiana University School of Dentistry.
authors: F
authors: F
authors: Lippert
mesh_terms: D000149:Acidulated Phosphate Fluoride / Q000737:chemistry; D001628:Beverages; D002327:Cariostatic Agents / Q000737:chemistry*; D019343:Citric Acid / Q000737:chemistry; D004058:Diffusion; D005459:Fluorides / Q000737:chemistry*; D005460:Fluorides, Topical / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing; D019904:Polymethyl Methacrylate / Q000737:chemistry; D012464:Saliva, Artificial / Q000737:chemistry; D012995:Solubility; D013997:Time Factors
chemical_list: D002327:Cariostatic Agents; D005460:Fluorides, Topical; D012464:Saliva, Artificial; C454339:cavity shield; C074808:NuPro; D019343:Citric Acid; D000149:Acidulated Phosphate Fluoride; D019904:Polymethyl Methacrylate; D005459:Fluorides
keywords: Fluoride varnish; dental erosion; fluoride release