Light radiation used in teeth bleaching treatments is useless and dangerous, according to recent research. The best dressed tooth whitening treatments  use a light source, which is believed to help improve the oxidizing effect of the bleaching agent, hydrogen peroxide. However, these lamps that are becoming a popular spa treatment make no difference, according to a study in the journal Photochemical and Photobiological Sciences, and may be dangerous for the client and the operator.

Researchers form the Nordic Institution of Dental Materials investigated 7 different bleaching systems that were commercially available on the Scandinavian and US markets in 2005. Using human molars donated after extraction, the team bleached one half of the tooth following the manufacturers’ recommendation and the other was left as a control. Half of the bleached teeth received both the bleaching gel and the radiation and the other half just the bleaching gel.

The team then went on to investigate the light sources to see whether the treatment time exceeded the recommended exposure times to such radiation. According to the study, there was no statistical difference in the color change of the teeth with bleaching gel and radiation and those treated simply with the product.

Although the study acknowledges that the exposure to clients and operators of the machinery will vary greatly between clinics and treatments, it concludes that the use of optical radiation in teeth bleaching poses a health risk. Clients may be exposed to up to 60 minutes of radiation to the teeth and mouth area. In addition, depending on the placing of the lamps and the protection worn, clients may experience a dangerous level of radiation to the eye.

These two factors, coupled with the fact that there were no discernible benefits from the radiation, led the researchers to advise against using light-assisted tooth bleaching.