Stannous fluoride was used (under the trade name Fluoristan) in the original formulation of the toothpaste Crest., though it was later replaced with sodium monofluorophosphate. However it is the active ingredient in Crest Pro Health brand toothpaste according to the label on the box and the tube. Crest Pro Health also issues a warning on the tube that stannous fluoride may cause staining; and that by proper brushing this can be avoided; and that their particular formulation is resistant to staining.
Used in combination with abrasives that contain calcium, sodium fluoride is ineffective; stannous fluoride remains effective when used with such abrasives. Stannous fluoride can cause surface staining of teeth, but these stains are not permanent.