Over 10 years of clinical use of teeth whitening products containing 10% carbamide peroxide have not shown any damage to existing fillings. The issue is not “damage” to existing restorations; rather, keep in mind that existing restorations such as tooth-colored fillings, crowns, bonding, veneers, and bridges do not lighten. This means that any pre-existing dental work may need to be replaced to match the new tooth shade achieved in the natural teeth, should a bleaching process proceed.