Hydroxyapatite (HAP), safe if swallowed, is an ideal fluoride substitute in toothpaste and mouthwash for people of all ages, including young children, the authors wrote. "More studies now show that ...

but young children do not spit out toothpaste reliably. Hydroxyapatite is a way to sidestep the fluoride controversy. It offers the anticavity benefits of fluoride, but without the risks.