Strips

Strips are the easiest of all teeth-whitening products to use, which is why they are the most popular. They come in a box with instructions on their use. Some strips need to be worn for 30 minutes, twice daily for about 3 weeks to see results; others need only be worn for up to 20 minutes once a day for 2 weeks—just make sure you read the label.

The strips adhere directly to your teeth, and contain bleaching ingredients that whiten as they sit on your teeth. Once removed from your teeth, you're done! Just be aware: you may see some sensitivity where the strip was placed, but it should go away within an hour or so of use.

As far as cost goes, Crest Whitestrips can range anywhere between $15 and $50 depending on type and quantity!

Gels

Teeth whitening gels are applied to the teeth using a small brush or a thin strip. These gels contain an active ingredient that helps remove stains and discoloration from the teeth. Gels may contain hydrogen peroxide (HP) or carbamide peroxide, which breaks down into HP when it comes in contact with water molecules in your mouth.

Gels are usually used for about two weeks. You apply the gel twice daily for 30 minutes each time, typically after meals and at bedtime. Most gels should be applied only to your front teeth, but some brands of gel can be applied to all of your visible teeth.

Trays

Trays are a good option for people with sensitive teeth. The whitening gel is applied to a tray that fits over your teeth. Because trays cover more of the tooth than strips, they are more effective in whitening. However, the results may take longer to see than with other methods.

Toothpaste

Toothpaste is a mechanical cleaning product that employs the physical act of scrubbing to remove stains. Some toothpastes also contain bleach, which acts as a whitening agent when it comes into contact with teeth. But, toothpaste is not usually considered an effective treatment for deeply stained teeth, and shouldn't be used in lieu of professional treatments like deep bleaching or lumineers.

While highly recommended as a daily use product and stain preventative measure, toothpaste is better suited to maintaining the results of professional treatments than it is to providing those results itself. Toothpaste should be used in conjunction with professional treatments wherever possible.