Stannous Fluoride is less stable

Lastly, Fluoride comes in different salt solutions so it can remain stable until solublized into the active fluoride ion in water or saliva. Neutral Sodium Fluoride is most common in toothpastes because it has long shelf life and can be easily flavored. Stannous Fluoride is less stable and more disagreeable in taste, but the Stannous or Tin ion has shown some trends towards reducing gum inflammation. Other compounds exist, but the active ingredient remains the fluoride ion.