Toof

Soon, you might get tooth regeneration instead of fillings for your poor diet, lack of flossing, and generally poor oral hygiene.

Scientists are beginning to find the right solutions of chemicals to rebuild decayed teeth, rather than merely patching their holes. Enamel and dentin, the materials that make teeth the strongest pieces of the body, could replace the gold or ceramic fillings that are currently used.

While regrowing teeth from scratch is still a decade away, the ability to use some of the body's own building materials for oral repair would be a boon to dentists, who have been fixing cavities with metal fillings since the 1840s. It turns out that not only are enamel and dentin remarkably strong and long-lasting, but they can repair themselves.

The outer covering of teeth is enamel, which the body makes it by growing tiny mineral crystals in a highly regular crystal lattice. Underneath that ceramic-like covering, dentin is like hard clay reinforced by fibers of collagen, similar to the way adobe bricks contain clay reinforced by straw fibers. Like any mineral, they are susceptible to what is essentially erosion. Acids, like those produced by bacteria or Coca-Cola, demineralize the enamel of the teeth. Usually the body is constantly repairing small amounts of damage but when the body's defenses become overwhelmed, bacteria break through into the dentin below, and you get tooth decay (a cavity, creep).

The acid produced by the bacteria eats into the minerals in the dentin, turning it mushy and useless. Normal dentin is twice as stiff as pinewood, but damaged dentin is more like rubber, which makes it pretty hard to chew with. New work that focuses on regrowing dentin in damaged teeth with the help of a calcium-containing solution of ions (electrically charged particles) is seeing publication this month. By putting a layer of the solution on individual test teeth, scientists have already been able to remineralize some parts of the teeth. The current challenge is to get the crystals to regrow throughout the dentin.

To heal properly, the crystals need to form from the bottom of the tooth up to the enamel, but there is the potential that the next five or so years could yield that result.