The scientific consensus is clear: kids should always brush with fluoride toothpaste. The American Academy of Pediatrics, American Academy of Pediatric Dentistry, and American Dental Association all agree on this point.
Fluoride is important because it strengthens enamel, protecting teeth from cavities. Toddlers will likely swallow their toothpaste, but you shouldn’t worry. The amount of toothpaste you should use for toddlers — a dab the size of a grain of rice — has about the same quantity of fluoride that dentists give children through supplements.
Over time, swallowing large amounts of fluoride can lead to white spots on teeth, so be careful to not use a big dollop for kids, and make sure the toothpaste is out of reach for them when you’re still helping them brush.