There is some evidence to support that cavities can be healed naturally by remineralizing the teeth. I made this last week and already my teeth feel cleaner and are looking whiter. I had heard about the properties of Xylitol in preventing tooth decay, but I recently learned that Bentonite clay is also great for teeth as it is full of minerals and draws out toxins. I also added baking soda for whitening, and cinnamon and clove for taste and for their antibacterial properties. This is adapted from a recipe I found on a highly useful website called Wellness Mama.
Here is what I used:
2 oz bentonite clay
1 tablespoon each xylitol, baking soda and ground cinnamon
1 teaspoon ground cloves
Mix it all up in a small jar and dip your toohbrush (and paste) at least once a day when you brush your teeth. Tastes great too!