Fluoride uptake from NaF/pyrophosphate anticalculus dentifrices in vitro: effect of pyrophosphate dose

Fluoride uptake from anticalculus dentifrices containing combinations of sodium fluoride and variable doses of soluble pyrophosphate has been evaluated in an in vitro fluoride uptake model. Artificial carious lesions were treated for 30 minutes in 25% w/w saliva slurries of dentifrices. Fluoride uptake into the partially demineralized enamel was assessed by microdrill biopsy. Results show equivalent fluoride uptake for dentifrices containing 0.243% sodium fluoride in combination with 0, 4.0 and 5.0% soluble pyrophosphate. These results, coupled with analytical measures of available fluoride, suggest no negative effects of pyrophosphate on fluoride availability or access to artificial carious lesions for soluble pyrophosphate concentrations up to 5.0% in a conventional (1,100 ppm fluoride) sodium fluoride dentifrice system.