The Australian Dental Journal reports that milk fortified with amorphous calcium phosphate (marketed here in the US as ACP or Recaldent) remineralizes enamel 81-164% more than your standard milk.  I've seen firsthand how amorphous calcium phosphate can remineralize damaged teeth .   If ACP-fortfied milk ever makes it to the states, it could have a greater effect on preventing cavities than any municipal water fluoridation effort.  (and with less angry anti-fluoride comments on my blogs, too.)