Having pearly white teeth is a great reason to smile. It seems like over time your teeth tend to form that yellowish build-up that's none too pleasing to the eyes. Before taking a bite out of your teeth-whitening options, it's important to consider what causes teeth discoloration. Believe it or not, medications can actually dull the color of your teeth. Some medications can even cause permanent staining. Consult with your dentist to find out which prescriptions can have lasting effects on your chompers. When it comes to fluoride, you can have too much of a good thing. An excess of fluoride can lead to white spots on your teeth. Among the leading drink dangers are coffee, tea, red wine and soda, all of which can lead to staining. Blueberries, soy sauce, cherries and cranberries can also cause some unsightly spotting. Smoking also causes teeth staining. Last but not least, bad brushing habits can contribute to staining. The good news is there are things you can do to brighten your teeth.