title: [Evaluation of acid diffusion and fluoride selective electrode to measure the total fluoride in toothpastes].
abstract: OBJECTIVE
  To evaluate the reliability of a method of measuring the total fluoride in fluoride-containing toothpastes with acid diffusion and fluoride selective electrode.
  
  
  METHODS
  Four brands of commercially available non-fluoride toothpastes and fluoride-containing toothpastes were sampled. Fluoride was extracted from the toothpastes in 2 mol/L HC10(4) at room temperature overnight and then subjected to the measurement with fluoride electrode.
  
  
  RESULTS
  Fluoride recovery of the non-fluoride toothpastes containing calcium as abrasive by this method was 99.5%-100.5%, more than 94% of total fluoride was measured from the marketed fluoride toothpastes, and the variation coefficient of this method was less than 1.54%. While the abrasive was silicon, the fluoride recovery of the non-fluoride toothpastes was 83.4%, and 89.7% of total fluoride was measured from the marketed fluoride-containing toothpastes.
  
  
  CONCLUSIONS
  The amount of total fluoride in the calcium containing toothpaste can be detected simply and accurately measured by acid diffusion and fluoride selective electrode.
authors.affiliation: Dept. of Preventive Dentistry, Peking University School of Stomatology, Beijing 100081, China.
authors.forename: Xiao-Ling
authors.initials: XL
authors.lastname: Wang
authors.forename: Chuo-Yue
authors.initials: CY
authors.lastname: Cheng
authors.forename: Yao
authors.initials: Y
authors.lastname: Ge
authors.forename: Qin
authors.initials: Q
authors.lastname: Wang
mesh_terms: D002118:Calcium; D004566:Electrodes; D005459:Fluorides; D010710:Phosphates; D015203:Reproducibility of Results; D012969:Sodium Fluoride; D014100:Toothpastes
chemical_list: D010710:Phosphates; D014100:Toothpastes; C012980:fluorophosphate; D012969:Sodium Fluoride; D005459:Fluorides; D002118:Calcium