Evaluation of total pH and soluble and ionic fluoride concentrations in dentifrices commercially available in Brazil.
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.
Bardal
Priscila Ariede Petinuci
PA
Department of Community Health, Bauru Dental School, University of São Paulo, Brazil.
Olympio
Kelly Polido Kaneshiro
KP
da Silva Cardoso
Vanessa Eid
VE
de Magalhães Bastos
José Roberto
JR
Buzalaf
Marília Afonso Rabelo
MA
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
D002327:Cariostatic Agents; D003802:Dentifrices; D007477:Ions; D010710:Phosphates; C012980:fluorophosphate; D012972:Sodium Hydroxide; D012969:Sodium Fluoride; D005459:Fluorides; D006851:Hydrochloric Acid