Trial & Error
Over the years, many different ideas were explored to achieve better and faster teeth whitening. Stronger peroxide-based formulas proved to be too harsh on the gingiva. And in the 1970s, they even tried using heating lamps to add heat energy. The radiant heat produced by heating lamps was so intense that it caused overheating of dental pulps, sometimes even necessitating endodontic therapy. Oops! Back to the drawing board.
Then, we saw the influx of photon energy techniques using bleaching lights and lasers. This was a big fad for a while, but the science never backed up these bleaching lights and laser approaches. The fact is that the breakdown of hydrogen peroxide is an exothermic reaction. So adding any type of energy, including photon energy, actually works against the reaction. Again, a lot of ideas were triedwithout concern for actual science. Obviously, dentists found the results of in-office whitening with lights and lasers was still extremely unpredictable and of very short duration. Either the whitening didn’t work at all or the whitening quickly relapsed within a very short time after treatment.
In an effort to reduce patient complaints, many dentists took it upon themselves to send their patients home with whitening trays and at-home whitening gel after the in-office whitening, because they understood that at-home tray whitening was at least somewhat effective. Again, this had nothing to do with true science.
This un-scientific protocol (with or without bleaching lights or lasers) has now become the standard whitening approach utilized by nearly all whitening systems. But it was not based on an understanding of science. It was simply a series of educated trial and error.
