For most people, the treatment will last for many years. Your teeth have become stained in the first place from consuming the foods and beverages. Upon the completion of your initial bleaching process, your teeth are restored close to their natural white color. Exposure to foods, drinks (especially coffee, colas and red wines), smoking and other consumables will gradually darken teeth again over time. You may want to periodically bleach your teeth. After an initial treatment, most people do touch-ups about once every 6-12 months.