The acids in plaque dissolve the enamel, creating holes called cavities. Many people think that only children get cavities, but changes in your mouth as you age make them an adult problem, too. As. Dental Caries in Permanent (Adult) Teeth Note: Approximately 5% of adults age 20 to 64 have no teeth. This survey applies only to those adults who have teeth. Dental caries, both treated and untreated, in all adults age 20 to 64 declined from the early s until the most recent () National Health and Nutrition Examination Survey.