The prime ingredient to look for when choosing any toothpaste is fluoride. Fluoride is a naturally occurring mineral. Frequent use of toothpastes containging Flouride may lead to less cavity formation. Bacteria in your mouth feed on sugars and starches that remain on your teeth after eating. Fluoride helps protect your teeth from the acid that is released when this happens. It does this in two ways. First, it can reverse the early stages of acid damage by solidifying areas that have started to decay and second , fluoride makes your tooth enamel stronger and less likely to suffer acid damage.