How can I prepare for tooth whitening?

Before beginning any tooth-whitening treatment, talk to your dentist about whether you should have this treatment. Your dentist will usually ensure that you have a healthy mouth before treatment begins. He or she will usually check for and treat any infections, cracked or sensitive teeth, tooth decay, and periodontal disease. Before, during, and after using OTC tooth whiteners, you should not overuse tobacco, use certain antibiotics, eat certain foods such as blueberries, or drink large amounts coffee, tea, or red wine, because all of these items can cause staining.

Any cavities should be filled before any tooth whitening procedure.  Dentists will also want your teeth cleaned, most likely by a dental hygienist. Some dentists keep track of the whiteness of your teeth by taking before-and-after photographs to document how many shades your teeth improved.