Better lighten up on teeth whitening

By William Atkins
Friday, 30 January 2009 19:50

Science - Health

According to research performed by the Nordic Institute of Dental Materials, the use of ultraviolet (UV) and visible light lamps to increase the whitening effect of bleaching teeth is damaging to teeth, and is also dangerous to eyes and skin.


Many people use hydrogen peroxide to whiten their teeth when they become yellowed from smoking tobacco cigarettes and drinking red wine and coffee. Some people go the extra step and use “light-assisted” lamps to make the bleaching process work better.

Hydrogen peroxide (H₂O₂) is a pale blue liquid. It is a weak acid, which has strong oxidizing properties. Consequently, it is used as a bleaching agent for bleaching paper. Hydrogen peroxide is also used as an oxidizer, a disinfectant, an antiseptic, and (in part) as a propellant in rockets.

Thus, the researchers decided to see if these lamps help to whiten teeth during the bleaching process and, more importantly, if these lamps are safe to use.

They state in the abstract to their paper: “The use of optical radiation in the so-called light-assisted tooth bleaching procedures has been suggested to enhance the oxidizing effect of the bleaching agent, hydrogen peroxide."

"Documentation is scarce on the potential adverse effects of bleaching products and on optical exposure risks to eyes and skin.”

The researchers published their paper “In vitro efficacy and risk for adverse effects of light-assisted tooth bleaching” in the journal Photochemical & Photobiological Sciences (2009, DOI: 10.1039/b813132e), a publication of the Royal Society of Chemistry.

The authors are Ellen M. Bruzell, Bjørn Johnsen, Tommy Nakken Aalerud, Jon E. Dahl, and Terje Christensen.

How did they conduct their experiment? Please read on.