Buyer beware, when it comes to at-home tooth-whitening kits.
The Trading Standards Institute (TSI) found 18 out of 20 kits purchased contain illegally high limits of the bleaching agent hydrogen peroxide.
Hydrogen peroxide, also found in
hair dye, can aggravate
gum disease, cause sensitive teeth and can even cause chemical burns to the mouth.
One of the products sampled contained 230 times the legal limit of hydrogen peroxide, which is 0.1 percent.
Hydrogen peroxide works by forming unstable and destructive molecules that break down into water and oxygen. It reacts with the pigments that stain teeth and destroy the double-bond that gives the pigments their color, thereby producing whiter teeth.
To limit the staining of your teeth in the first place, stay away from common culprits like red wine, coffee, tea and cigarettes, which over time gets absorbed into the tooth enamel.
Your best option is to consult with your dentist, who can recommend a treatment that is best suited for your current needs. Anyone with gum disease, for example, should stay away from hydrogen peroxide, or risk making their gums worse, which can
leak other toxins straight into your bloodstream.
BBC News June 26, 2007