It turns out that tooth decay and cavities are actually caused by a bacteria in food called Streptococcus mutans that attaches to the surface of your teeth and then slowly releases an acid that dissolves away the enamel. But it also turns out there's another type of bacteria called Lactobacillus paracasei that has a sugar on its surface that binds to the Streptococcus mutans, preventing it from attaching itself to teeth. So by engineering a candy featuring a dead version of Lactobacillus paracasei—so it doesn't cause any harm itself but still sticks to the bad bacteria—the researchers found the level of Streptococcus mutans inside the mouths of test subjects to be greatly reduced, minimizing the risk of cavities.
It doesn't mean you still shouldn't brush and floss regularly, but telling kids "you'll rot your teeth out" might not carry the same weight it used to.
Source: gizmodo.comAdded: 23 December 2013