I suggest talking to a toxicologist rather than a dentist. Fluoride in any amount is a toxin. The EPA has recognized it as a gold standard developmental neurotoxin; it is known to cause neurological defects in those exposed to it before birth or during early childhood. This effect has been confirmed by a hundreds of animal, epidemiological and case studies and reports - even at levels added to our water supply, .7 ppm. EPA scientists have recommended that the goal for fluoride in water should be 0 ppm.
General statements of opposition, the first two with scientific citations attached:
1. 2016 Letter to the American Thyroid Association from Richard Shames, MD, et al. (endocrine disruption & cancer) http://www.ehcd.com/wp-content/uploads/2016/02/2016_02_11...
2. 2016 Letter to the National Governors Association from consumer advocate Erin Brockovich, water specialist Robert Bowcock and “elite” whistleblower attorney, Michael D. Kohn (lobbying & advocacy) http://fluoridealert.org/wp-content/uploads/brockovich-20...
3. 2016 Letter from civil rights leader Ambassador Andrew Young (disproportionate harm): http://www.prweb.com/releases/2016AndrewJYoung/10/prweb13...
4. 2016 Statement from medical scholar Dr. Mark Hyman (health & politics) http://fluoridealert.org/news/mark_hyman_fluoride/
5. 2015 Statement from environmentalist Lois Gibbs (environmental justice) http://fluoridealert.org/wp-content/uploads/gibbs-2015.pdf
For those of you who prefer meatier scientific reading, I suggest these well cited items:
A. 2017 Comment to EPA from 2006 NRC panelist, Dr. K. Thiessen (science & harm) https://www.regulations.gov/document?D=EPA-HQ-OW-2016-062...
B. 2016 TSCA Petition to the EPA from AAEM, IAOMT, FAN, MAF, FWW, & OCA (neurotoxicity & regulations): http://fluoridealert.org/wp-content/uploads/epa-petition.pdf
C. 2003 IAOMT position paper opposing fluoridation (toxicity & carcinogenicity): https://iaomt.org/iaomt-position-fluoridation/