We can whiten teeth dramatically using various forms of hydrogen peroxide. One form, carbamide peroxide, is most often used in the form of a gel, and placed into a special tray that is custom-fitted to your teeth. The tray is worn in the mouth for one to four hours per treatment. When in contact with the teeth, the carbamide peroxide releases oxygen that releases the stain on your teeth. This process is safe and effective with only a few temporary side effects. This treatment can be applied at home under periodic supervision by your dentist.