Teeth are structures in the mouth that are individually squares or cubical-shaped with grooves intended for use in breaking down food for consumption. Teeth are naturally white or off-white in color, but build-up from foods and drinks such as coffee and tea over time can stain the white color and turn teeth yellowish and discolored. In this experiment, we'll use egg shells in order to explore how teeth are stained by drinking coffee, tea, and cola.