title: Evaluation of total pH and soluble and ionic fluoride concentrations in dentifrices commercially available in Brazil.
abstract: OBJECTIVE
  To verify the total (TF), soluble (SF) and ionic (IF) fluoride concentrations in the main Brazilian dentifrices for comparison and quality control according to the current Brazilian Ministry of Health Regulations, 2000.
  
  
  METHODS
  Nineteen brands, from 2 batches, fresh or aged at 45 degrees C/48 h, had their F concentrations and pH analyzed with a specific electrode and pHmeter. To analyze the TF, 0.25 ml of 2M HCL was added to 0.25 ml of the suspension of each dentifrice. This was kept at 45 degrees C/1 h and 0.50 ml of M NaOH and 1.0 ml of TISAB II was added. To assay SF and IF, after centrifugation, the supernatant was used and the same steps described above were followed for SF. The analysis of IF was made by adding 0.25 ml of the supernatant to 1.0 ml of TISAB II, 0.5 ml of M NaOH and 0.25 ml of 2M HCL. Paired t tests were used for statistical analysis.
  
  
  RESULTS
  The concentration of TF, SF and IF ranged from 555.7 - 1835.1; 449.3 - 1619.3 and 96.9 - 1534.6 ppm respectively. After aging, a significant reduction in the SF concentration (p = 0.00002) was observed, which did not occur for TF and IF (p > 0.05). Only the brand Colgate Baby presented pH 6.8. The other dentifrices had an alkaline pH, ranging from 7.1 - 9.9.
  
  
  CONCLUSIONS
  Although the term 'soluble' was suppressed by the new regulation, the dentifrices analyzed were in accordance to the Brazilian Ministry of Health Regulations, 1989.
authors.affiliation: Department of Community Health, Bauru Dental School, University of São Paulo, Brazil.
authors.forename: Priscila Ariede Petinuci
authors.initials: PA
authors.lastname: Bardal
authors.forename: Kelly Polido Kaneshiro
authors.initials: KP
authors.lastname: Olympio
authors.forename: Vanessa Eid
authors.initials: VE
authors.lastname: da Silva Cardoso
authors.forename: José Roberto
authors.initials: JR
authors.lastname: de Magalhães Bastos
authors.forename: Marília Afonso Rabelo
authors.initials: MA
authors.lastname: Buzalaf
mesh_terms: D001938:Brazil; D002327:Cariostatic Agents / Q000032:analysis*; D002498:Centrifugation; D003802:Dentifrices / Q000032:analysis*; D005459:Fluorides / Q000032:analysis*; D006801:Humans; D006851:Hydrochloric Acid / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007477:Ions; D010710:Phosphates / Q000032:analysis; D011786:Quality Control; D016037:Single-Blind Method; D012969:Sodium Fluoride / Q000032:analysis; D012972:Sodium Hydroxide / Q000737:chemistry; D012995:Solubility; D013696:Temperature; D013997:Time Factors
chemical_list: D002327:Cariostatic Agents; D003802:Dentifrices; D007477:Ions; D010710:Phosphates; C012980:fluorophosphate; D012972:Sodium Hydroxide; D012969:Sodium Fluoride; D005459:Fluorides; D006851:Hydrochloric Acid