Visiting the dentist
At least once a year.
If you buy your toothbrush or toothpaste at the chemist's, the pharmacist will recommend the most suitable one for you, and explain how to use it properly. If you do everything your parents and the pharmacists tell you to do, you won't have to visit the dentist so often, but even so you must pay the dentist a visit at least once a year, as it is very important to prevent disease.
Remember, if you take proper care of your teeth, you can help to fight tooth decay.