Whitening Product Safety
Some whitening products you get through dentists' offices as well as professionally applied (in-office) bleaching products have the American Dental Association (ADA) Seal of Acceptance, which tells you that the product meets ADA guidelines for safety and effectiveness. Currently, only dentist-dispensed home-use products containing 10% carbamide peroxide and office-applied products containing 35% hydrogen peroxide have this seal.
Over-the-counter bleaching products are not endorsed by the ADA, because the organization believes that professional consultation is important to ensuring safe and effective use. No whitening products using lasers are on the ADA's list of accepted products.
Several whitening toothpastes available in drugstores have received the seal, too. You can find a list at www.ada.org.
Not all manufacturers seek the ADA's Seal of Acceptance. This is a voluntary program that requires considerable expense and time on the part of a manufacturer. Just because a product doesn't have the seal does not necessarily mean that the product isn't safe and effective.
Teeth whiteners are not drugs and therefore aren't regulated by the FDA.
Choosing an Over-the-Counter Whitening Kit
Try to select a product that allows the mouthpiece to be customized. Some kits come with a tray that can be molded to some degree. These are better than others that come with a standard mouthpiece.
Look for online reviews and ask around to find out what others who may have already tried the kit you're considering think about it.
If at any time you experience a prolonged change in the color of your gums or an increased tooth sensitivity to hot or cold foods and beverages, stop wearing the mouthpiece and see your dentist immediately.