DEAR DOCTOR K: What is tooth decay? Is it the same as a cavity?
DEAR READER: Tooth decay is not the same as a cavity -- but tooth decay can lead to the formation of a cavity. Tooth decay (also known as dental caries) originates with plaque, the sticky, bacteria-laden film that collects on your teeth between brushings. In recent years, we've learned that many types of bacteria produce filmy substances that act like a protective foam.