You already know that teeth whitening works, but do you know how?

Stains on teeth can be classified in one of two ways: extrinsic or intrinsic. Extrinsic stains appear on the surface of your teeth. Intrinsic stains live between the microcracks in your enamel and deep within your dentin (the layer of your tooth underneath your enamel). Whitening toothpastes and mouth rinses may be able to remove some of the extrinsic stains on your teeth. But only teeth whitening agents can remove the stubborn extrinsic stains and the unsightly intrinsic stains that cause your teeth to look discolored.

Opalescence gels contain an active whitening ingredient (either carbamide peroxide or hydrogen peroxide) that penetrates your enamel to get to discolored molecules. Oxygen molecules from the whitening agents react with the discolored molecules in your teeth, breaking the bonds that hold them together. The oxygen molecules spread, whitening the entire tooth. As a result, you are left with a brighter, whiter smile.