Psychologists say that a child‘s habits are generally formed by the age of five years old. This is why pediatric dentists agree it’s important to start early on teaching proper dental care. Even a toddler can get involved in a routine mouth care regimen. This is the perfect time to teach your child about cavities, and prevention really is the best method! Cavities are caused by plaque, a slimy substance made up of sugars and starches that mix with the natural bacteria in the mouth. The plaque eats away at the tooth, causing painful cavities that will have to be fixed. It is no problem for a child to understand that brushing his teeth will help to ‘wash’ these plaque germs away.