A: The April Journal of the American Dental Association (JADA) contained a study done at a very well respected Italian University’s biomaterial and biomedicine department. They tested real teeth exposed to high-concentration of 38% hydrogen peroxide, commonly used for in-office whitening treatment.
The results showed no roughness alterations of the enamel surface under the scanning electron microscope, even with prolonged and repeated applications.
Several light activated methods are commonly used: Zoom, Rembrandt, Sapphire Whitening, and Brite Smile. Avoid flea market and trade show booth whitening "tents."