Most kids can start using whitening toothpaste around age 6 or 7. Some brands may have specific instructions for younger children. For example, Crest recommends that kids under 12 use a pea-sized amount of toothpaste and brush their teeth carefully to avoid swallowing it. You should also check with your child’s dentist before starting them on a whitening toothpaste regimen.
Whitening toothpastes work by either removing surface stains or by bleaching the teeth to make them appear brighter. They usually contain gentle abrasives, as well as hydrogen peroxide or other bleaching agents. While whitening toothpastes can be effective at brightening teeth, they won’t change the natural color of your child’s teeth. And, they may not be necessary if your child’s teeth are already healthy and white.