Teeth whitening or bleaching is a simple, non-invasive dental treatment to change the color of natural tooth enamel to enhance the beauty of your smile. Teeth whitening may be accomplished in a dental office or at home. The procedure uses a chemical called peroxide to bleach or whiten the teeth. The concentration of peroxide may vary depending on the type of procedure. Teeth whitening may be beneficial for patients with normal wear of the outer tooth layer that have yellow, brown or stained teeth, those with fluorosis, a discoloration due to excessive exposure to fluorides during tooth development and for those with stained teeth due to medications such as tetracycline.