Even if you take good care of your teeth, they can eventually stain from a number of outside influences or even as the result of infections and decay. Cigarette smoking and drinking tea, coffee, and wine will turn your teeth yellow. Internal dental infections or thinning enamel can make teeth appear gray or brown. Regular brushing with toothpaste cannot remove these stains. However, Zoom! teeth whitening and aesthetic restorations are effective ways to get your teeth looking white again.