In general, if you want to have long-lasting whitening, then you need to care for your teeth by practicing oral hygiene, getting regular cleanings, and minimizing your consumption of staining foods and beverages. However, immediately following your appointment, you will want to be extra cautious. Within 24-48 hours after your in-office bleaching appointment, your teeth are more vulnerable. Avoid staining and acidic foods during this time. Coffees, sodas, teas, wines, highly dyed foods, brightly colored and acidic fruits should all be avoided.