Fluoride Availability and Stability in Children's Toothpastes in Uruguay.

PURPOSE: The purpose of this study was to evaluate the availability and stability of fluoride in children's toothpastes in Uruguay. METHODS: Six commercial brands of children's toothpaste available in Uruguay were tested. Analyses were made when the dentifrices were purchased (fresh samples) and after one year of storage (aged samples). Total fluoride (TF) and total soluble fluoride (TSF) concentrations were determined using an ion specific electrode. RESULTS: Four of the children's dentifrices showed TF concentration similar to that specified on the package. Three products showed similar concentrations of TF and TSF with no variations after the one-year storage period. Two dentifrices showed an initial insoluble fluoride concentration greater than 50 percent, which increased with toothpaste aging. CONCLUSION: Most tested toothpastes showed a decrease in the soluble fluoride content with aging. The high quantity of insoluble fluoride found in two tested dentifrices may compromise their anti-caries efficacy.