Why does drinking milk strengthen teeth?

Teeth. Calcium contained in the milk helps strengthen teeth while they are being formed(before eruption) and after eruption for the next three years as the root completely forms. It does not help adult teeth, however you do still need the calcium for bone health and you can get it from many food sources.
Calcium. Milk has a lot of calcium, which is a major part of the crystalline structure that makes your teeth & bones hard.