There are many choices for bleaching teeth at home, the most common include:

• Tooth whitening strips and gels. Applied directly to the teeth with a brush or a thin strip, these peroxide-based tooth bleaching products usually need to be applied once or twice a day for 10 to 14 days. Results last four or more months and may cost from $10 to $55.
• Tray-based tooth bleaching systems. With this teeth whitening option, a mouth guard-like tray is filled with a peroxide-based bleaching gel or paste and placed over the teeth for one to several hours a day for up to four weeks. You can buy tray-based tooth whitening systems over-the-counter or have one custom-fitted by your dentist. The cost can range from $300 to $600.

Tooth-whitening works best for people with yellow teeth and is less effective for people with brown or grey teeth.