Teeth Whitening: More Than a Superficial Change

Whitening treatments involve more than just the surface of the teeth. Read on to reveal the science behind a brighter smile.

Every time you brush your teeth, abrasive compounds and chemicals wear away small particles, leaving a cleaner surface. If toothpaste doesn’t seem to get at yellowish stains, that’s because they’re not actually on the surface—they’ve seeped into the dentin, the more porous layer between the enamel and the root of each tooth. To reach this deeper discoloration, scrubbing won’t work. Instead, dentists deploy basic chemistry: a solution of hydrogen peroxide (or carbamide peroxide, which turns into hydrogen peroxide when it encounters saliva) is left to sit against the teeth in gel-filled trays or strips, breaking the chemical bonds of particles that contain unwanted coloration.

Some formulas are designed to be activated with an LED, laser, or halogen light whose specific wavelength is supposed to accelerate the breakdown of these particles. Although studies as to the light’s effectiveness vary, the basic chemical process remains the same, and light-activated systems may work more quickly.