How to brush your teeth properly
14 July 2015 Last updated at 13:35 BST
A big group of doctors say children should be supervised until they're 14 when brushing their teeth.
The Royal College of Surgeons claim it is necessary because so many kids have teeth that are rotting.
Experts say a lack of proper brushing is often to blame.
So, how do you make sure you brush your teeth properly?
Newsround got Dentist Ben Atkins, from the British Dental Health Foundation, to explain.