You should start brushing your baby's teeth as soon as the very first tooth appears, which is usually around 6 months of age. Before teeth emerge, it's recommended to gently clean your baby's gums daily using a clean, damp washcloth or sterile compress. Once the first tooth comes in, use a small, soft-bristled toothbrush and a tiny smear of fluoride toothpaste to brush gently twice a day. Continue helping your child brush until they can do it well themselves, typically by around 7 or 8 years old.