Our system will remove most stains with a gentle action that whitens your teeth. As the active ingredient in the gel (carbamide peroxide) is broken down, oxygen acts upon the stained organic deposits, which oxidizes them into a white color. This process makes the overall tooth color closer to its natural unstained color. Your tooth structure remains unchanged. Years of clinical tests have demonstrated the safety and effectiveness of this system. Over 95% of people treated achieve some level of tooth whitening. Crowns, bridges, bondings, and fillings do not lighten.