Crest 3D White Whitestrips (prices vary) have become the standard for at-home teeth whitening products. The original Crest Whitestrips whitening kit comes with a 10-day supply of strips which you apply to your upper and lower teeth twice a day for 30 minutes. The fact that you have to dedicate an hour a day to teeth whitening may put some people off; not everyone has the time or inclination to do this. You may also notice some white spots on your teeth at the early stages of treatment, but these usually go away in time. As far as effectiveness goes, Crest White Strips are a very good choice. They provide you with noticeable whitening in less than two weeks.

Anyone who's used whitening strips knows that it can be difficult to keep the strips on your teeth for the full 30 minutes of treatment. Strips can slip off, curl up, and generally move off the areas where they need to be. Rembrandt Form-Fit Whitening Strips are designed to adhere to your teeth so that you can get the full effects out of each whitening treatment. The course of treatment for this product is only 5 days when used once per day, so you don't have to make as long a commitment to Rembrandt as you would to Crest.

Rembrandt Form-Fit Whitening Strips are on the small side, so if you have a big, wide smile, it might not target all your visible teeth. The whitening power of these strips may not be visible until late in the treatment, and they provide subtle yet noticeable whitening results.

Whitening Trays

Whitening trays are similar to whitening strips, but some people may find they're easier to use. These flexible plastic trays are filled with whitening solution, which is included in the kit. They're shaped to fit directly over your teeth so the period you have to wear them can be a bit more comfortable. Of course, not everyone finds whitening trays to be this convenient; some trays can ooze and leak solution into your mouth.