How can one get a cavity?

Diet/Hygiene: Dental cavities are caused by acid that is produced by the bacteria in our mouths. The carbohydrate in our diet (especially the liquid sugars) are metabolized by the bacteria in dental plaque into organic acids. If the plaque is allowed to remain on the tooth, the acid creates a hole in the tooth we call a cavity. Reduce dietary carbohydrate, remove plaque and use a Fluoride toothpaste.