Gem Spa uses state of the art "PRO20 LED lasers" — sensitive teeth are no worry here. Our patented formula has a built in conditioner that conditions while whitening, and most clients have no sensitivity whatsoever. Professional teeth whitening uses LED lasers to open the millions of little pores on the teeth to lift stains. The peroxide gel activates when temperature increases, something that happens in a slow manner just from application in the mouth. The teeth whitening machine accelerates the rate that the peroxide activates - so users see a rapid shade improvement. People with healthy smiles may see a shade increase of 4 - 10 shades in just one sitting!