hen
water fluoridation first began in the 1940s, dentists believed that fluoride's main benefit came from ingesting fluoride during the early years of life. This belief held sway for over 40 years. However, it is now
acknowledged by dental researchers to be incorrect. According to the Centers for Disease Control, fluoride's predominant effect is
TOPICAL (direct contact with teeth) and
not systemic (from ingestion).
Hence, there is no need to ingest fluoride to derive it's purported benefit for teeth.
As stated by the US
Centers for Disease Control:
"[L]aboratory and epidemiologic research suggests that fluoride prevents dental caries predominately after eruption of the tooth into the mouth, and its actions primarily are topical for both adults and children"
(CDC, 1999, MMWR 48: 933-940).