How to get a mouthful of natural-looking pearly whites.

Yunhee Kim

So you got a little bleach-happy and overused your whitening product of choice. Now your teeth are Day-Glo white. Don't panic. "After whitening, the color will naturally tone down in a day or two," says Nathaniel Redmond, D.M.D., a spokesperson for the Academy of General Dentistry.

To prevent future spells of supernova smile, complete a cycle of at-home bleaching only once a year, and monitor the color of your teeth as you go. Stop the process when your teeth reach a natural shade of white.

Not sure what the right natural white is for you? Before you bleach, ask your dentist to show you a shade guide marked with the starting color of your teeth and an appropriate ending shade, so you can keep track precisely.