A question very commonly asked by parents, and one that has a different answer depending on who you are. My dentistry colleagues would suggest “the earlier the better” approach and tend to recommend as early as 1 year, mainly to get kids used to sitting in the chair and for parent education regarding teeth cleaning. I advise parents to start cleaning their child’s teeth as soon as they erupt, using a gauze and water, and later using a soft child-friendly brush. Children’s toothpastes are safe to swallow and, in any case, I’d rather see cavity-free teeth than worry about a little fluoride being consumed.
Of course, I always warn of the dangers of putting the child to sleep with a bottle and illustrate the problem with stories of rotting teeth and huge dental bills. Personally, I usually suggest kids see the dentist when most of the primary teeth have erupted around 2 years and every 6 months thereafter.