Teeth can often be whitened by the several new techniques of "bleaching" available today. The most common method used is the "in-office" method where a strong bleaching agent is placed over the isolated teeth and a special light is used to assist the bleaching material lighten the teeth. This method is generally more controlled and probably better for people who have tetracycline stains or streaks on their teeth. The "home" techniques involve making trays which fit into the mouth and these are then filled with bleaching materials. When worn for a few hours a day, noticeable results are seen generally within a few days to a couple weeks. Results vary from individual to individual, your dentist will be happy to to help you decide which method works best for you. Some of the factors involved include the intensity of the stains, whether or not you have fillings or crowns on your front teeth as well as what may have caused the stains.