How it works: The key to keeping your teeth sparkling after using any of these treatments is to maintain your whitening routine. Try to cut back on food and drink that cause staining, especially within 24 hours after using a bleaching product, and swish with water after eating or drinking. Coffee addict? Try switching to iced coffee and drinking with a straw. If you're into tea, chug it. "Tea often stains more than coffee, because people tend to hold it in their mouths a lot longer when they drink it," says Deutch.

What to use: Deutch recommends maintaining your oral care by using a whitening fluoride rinse, such as Listerine Healthy White Restoring Anticavity Mouthrinse, $11.79, and cleaning hard-to-reach stains with Oral-B Glide 3D White Whitening Plus Scope Flavor Floss, $3.99.

When you'll see results: Continually