Here we go.. I found it. This is how tooth remineralization
   works. Basically, you have to have the right ions in the mouth
   and the tooth remineralization happens automatically. Dogs eat
   bones, they breath, their teeth are always white.

   Same with people.

   Minerals good for tooth rebuilding are primarily calcium and
   magnesium. Need both. IF there's gunk in the way (plague)
   process doesn't work very well. Some foods like strawberries
   remove plague... somehow. and I think I'm mispelling plague.