Light-emitting diodes, or LEDs, release energy in the form of photons and have all sorts of functions in our lives (remote controls, digital clocks, traffic signals, you name it). Blue and red LEDs are medically proven to relieve pain, increase circulation, enhance gum health, freshen breath, and, yep, whiten teeth. This is one of the most advanced over-the-counter whitening systems you can buy, and it works wonders. Blue light helps reduce bacteria, causing a whitening effect, while red and infrared lights actually improve gum health by increasing blood flow. If you want an extra boost of whitening power, use this along with your favorite whitening gel.