1) A highly toxic carcinogen ingredient in toothpaste, with scientific evidence of near zero improvement in tooth health, and a much higher risk of dental fluorosis, as well as not at all proven to be noticeably more or less effective than non-fluoridated toothpaste.
2) Industrial waste sold to primarily American (and some UK) local governments and added to their public water supplies, and often forced upon by their Federal government, which is a highly toxic carcinogen through extended use known to put holes in brains, shut down vital organs, significantly contribute to bone loss, significantly lower life expectancy, significantly lower IQ in fluoridated populations contrary to non-fluoridated populations, and make it's citizens less aggressive (more docile).
3) A primary ingredient in most anti-depressants.
Fluoride toothpaste and fluoridation of water supplies was pushed heavily by author of highly successful 1920's books Propaganda and Spin, Edward Bernays, in his support of the Fluoridationists of the Public Health Service.
It is illegal to be added to public water supplies in most of the world (i.e. Germany where it is considered "medication without consent."), and the Japanese government once considered its use to combat a growing suicide rate but received a great deal of resistance from it's citizens.
If you swallow your toothpaste, call the CDC!
(don't think rinsing it out you will completely avoid absorbing it)
If you drink a glass of water, you've ingested as much fluoride as a standard application of toothpaste, call the CDC!
If you take anti-depressants, call the CDC!
If you think are living too long past their usefulness, support fluoridation at your local government
If you have any concerns, internet search the word "fluoride"