Each year in the United States there are over 3 million cavities diagnosed. So you are not alone if you or your children have cavities. In fact, cavities are the number one reason kids miss school. 90% of all adults have a cavity at some point in their life. If you have visited the dentist recently and they found a cavity, you may be wondering what happens next. The answer to this depends on how severe the cavities are. But in most cases when you develop a cavity, and it is caught early, then your dentist will be able to do a filling, which will fix the issue early.