According to the teeth whitening experts, the first 24-48 hours after teeth whitening is critical. After the whitening process, the pores or dental tubules on your teeth are open and they are very susceptible to staining. You should give your teeth a chance to recover before consuming food and beverages that may stain your teeth. Anything that stains your white shirt will stain your teeth. You may want to wait at least 36-48 hours to consume food or beverages that may stain teeth, such as coffee, tea, green tea, wine, etc. Maintenance with at-home trays is very important to keep up the whiteness.