Every two years, the WHO updates their Model Lists of Essential Medicines. Fluoride was first added in 1979 as sodium fluoride tablets (1.1 mg NaF/0.5 mg fluoride) "for use in the prophylaxis of dental caries where water supplies are not fluoridated." With the latest update in September 2021, the WHO now recognizes fluoride "in any appropriate topical formulation" for the prevention of dental caries.