Making healthy food, snack and drink choices are an important part of taking care of your teeth. After you eat, bacteria go crazy over the sugar on your teeth. The bacteria break it down into acids that eat away tooth enamel, causing holes called cavities. Plaque also causes gingivitis ( jin-juh-vi-tis), which is gum disease that can make your gums red, swollen, and sore. Limit the frequency of sugary drinks or snacks.