Effect of a strontium complex on fluoride uptake by artificial caries lesions and sound enamel in vitro

The effect of a strontium-polyacrylate complex on fluoride uptake by bovine enamel was determined. A salivary pellicle was formed on sound enamel and enamel with artificially formed caries lesions. Ten specimens of each were treated with solutions containing (A) 225 ppm F, (B) 225 ppm F plus Sr complex, (C) 200 ppm F, 0.1 M phosphate, pH 4.5 or (D) placebo for 1 h and then washed 24 h to remove labile fluoride. Analysis of ten thin layers of enamel showed that, on both enamel types, solution (C) deposited the largest amount of fluoride. The strontium complex decreased fluoride deposition, particularly in the outermost layer.