Strontium dichloride
Strontium chloride (SrCl2) is a salt of strontium and chloride. SrCl2 is useful in reducing tooth sensitivity by forming a barrier over microscopic tubules in the dentin containing nerve endings that have become exposed by gum recession. This kind of barrier protection for tooth hypersensitivity has, however, been superseded by other toothpaste formulations and ingredients designed to be nerve calming agents instead. Such strontium chloride toothpaste formulations may subsequently not be available for sale anymore in certain parts of the world.