Be mindful of "too good to be true" claims. In addition, while reading labels, know that the labels can be legally misleading. For example, candies that have the National Diabetic symbol on it do not necessarily mean the product is low in sugar. This organization sells the right to use it's symbol.
I would think that what you might be talking about might be sugarless candy. The sugar in candy is what causes cavities in your teeth. It is also what causes the painful sensation you get when you have cavities and eat candy.
I tend to be leery of these kinds of claims. Most of these things are "all natural" and so they don't have to be tested by the Food and Drug Administration. Because of this, they can make any kind of claim they want to about what their effects are. Until they come out with something that is clinically proven, I would not believe it either.
There are discovered some flouride free mints, that contain an ingredient which combines calcium and arginine and fight against cavities.
The active ingredient from mints is raising the ph level, so that, combined with saliva, it creates a layer that protects the teeth.
The active ingredient is called Cavistat and it also helps in protecting the minerals from teeth against disolving.