When your child’s first tooth appears, begin brushing with water. When your child is 3, they can begin brushing their own teeth with parental supervision to ensure that only a pea-sized amount of fluoride toothpaste is used. By the age of 6, your child should be brushing their teeth independently. Teach your child to spend 30 seconds in each quadrant, making sure to brush the front, back, top, and sides of each tooth. The above video can be used to help your child gauge the amount of time they should spend brushing their teeth.