How long do children have to brush their teeth to get them really clean?

The American Academy of Pediatric Dentistry estimates that as many as 40 percent of children of kindergarten age have cavities, infections of the teeth. This can be prevented with appropriate dental care, which should begin before eruption of the first tooth. In the 2009 guidelines of infant oral health, AAPD recommends a series of steps to maximize a child’s dental health.

Daily brushing and flossing reduces impacted food particles and dislodges plaque, but the length of time your children spend brushing is not as important as how often and how well they brush. There are various techniques for children of different ages, so you should follow your dentist’s advice on how to handle your child’s brushing.

But certain rules apply to all kids: they should brush at least twice a day and use no more that a pea-sized amount of toothpaste. (Too much toothpaste can actually erode tooth enamel.) It’s also important to know what foods cause cavities so you can make sure your child brushes after eating them. Sugary foods (such as candy and sweet breakfast cereals) increase the growth of cavity-causing bacteria, while acidic ones (such as fruit, vegetables and soda) may erode the protective enamel on teeth, allowing more cavities. Regular cleanings at the dentist also help.

Dr. Mark Diamond is a pediatrician at the Children’s Hospital of Pittsburgh.