Whitening your teeth is one of the easiest ways to get a beautiful smile. Bleaching lightens surface stains caused by coffee, tea, soda, wine, food, smoking, and age. A prescribed bleaching tray is custom made for each patient. The patient then applies the bleaching gel each night for 7 to 10 days. While professional teeth whitening produces aesthetic, long-lasting results, bleached teeth may need touching up every year to maintain a bright, white smile.