Don’t Be Fooled by the Myth of Bleaching Lights and Lasers

There has been great controversy regarding the effectiveness and advisability of bleaching lights and lasers for well over a decade. Manufacturers of these products continue to claim that they add great benefit to the whitening process, but the science, published clinical studies (those studies not funded by bleaching light or laser manufacturers) and general consensus of dentists disagrees.

It is important to realize that the breakdown of hydrogen peroxide is an exothermic reaction.

Exothermic reactions require the release of energy (often in the form of heat) for the reaction to proceed. Bleaching lights and lasers are adding energy to the process in the form of photon energy.

According to Le Chatillier’s Principle of Chemical Equilibrium, trying to force energy back into an exothermic reaction that must release energy, may even impede the reaction. So where is the science behind the use of bleaching lights and lasers? There is none.

Dentists have also found that the use of a bleaching light or laser greatly increases the discomfort patients feel during and after whitening. Dentists have heard that this discomfort is due to heat and/or dehydration caused by these bleaching lights and lasers (which, by the way, is not true).

The fact is that various clinical studies have concluded that the increased sensitivity found using bleaching lights or lasers in combination with in-office whitening gels was not due to the heat and/or dehydration caused by the lights or lasers. Rather, it was found that the combination of high concentrations of hydrogen peroxide with photon energy from bleaching lights and lasers causes the pulpal neurons to produce significantly higher levels of Substance P — a neurotransmitter released by pain transmitting neurons in the pulp.

So turning on those lights and lasers could actually be turning up the sensitivity…and the pain!