" – Sometimes it seems that no matter how much you brush you just can't seem to brighten your smile. br br The problem’s not that your teeth are unclean; it's actually caused by staining or the natural discoloration of your teeth. Teeth can darken for a number of reasons. The most common is the natural tooth-yellowing effect from aging. Your teeth may also be stained from drinking coffee; tea or caffeine based soft drinks.br br With offices in North Chicago and Round Lake Beach, Den-Care Smile Center provides teeth whitening and tooth bleaching treatment to the following areas: Beach Park, Grayslake, Great Lakes, Gurnee, Lake Bluff, Lake Forest, Lake Villa, Libertyville, Lindenhurst, Mundelein, North Chicago, Round Lake Beach, Vernon Hills, Wadsworth, Waukegan, Winthrop Harbor and Zion.