Re: reverse cavities?

No, there is no way to reverse the cavities, however, if they are not deep enough (still on enamel), they do not always need to be "drilled , filled and billed" If they are indeed just in enamel and have not broken through into the dentin, you and your dentist can "watch" them, keep them very clean and give up refined carbohydrates. Sometimes they will re-mineralize.
In the event you do have fillings placed, I would not allow the dentist to use amalgam. Apparently there is a less toxic material in the market called diamond resin. Ask your dentist if he is familiar with it. Here is a good site to get information on the material:
http://www.biodent.com.au/diamondcrown.html

Dr V