Dental bleaching, or teeth whitening, is a cosmetic procedure designed to lighten teeth and remove stains and discoloration caused by aging, consumption of staining substances, and certain medications. The process can be performed in-office by a dentist using high-concentration bleaching agents and special lights or lasers for quick results, or at home with custom-made trays and lower-concentration gels over several weeks. Over-the-counter products, such as whitening toothpastes and strips, offer more gradual results. The active ingredients, hydrogen peroxide and carbamide peroxide, break...