How do bleaching lights work?
“Power bleaching” or light-accelerated bleaching uses the thermal effect of light energy to accelerate the bleaching process in the dentist office, using lower concentrations over shorter times.
Different types of lights (halogen, LED, plasma) are used for this procedure, generally with a blue light, i.e., the most effective wavelength to trigger the hydrogen peroxide reaction.
It should be pointed out however that there is no evidence that light in itself can activate the bleaching gel.
In fact, light-based activation – without photosensitising agents – is based exclusively on heating the gel.
The heat is then conveyed from the gel to the surface of the tooth which dehydrates it significantly, greatly increasing the risk of sensitivity.