Only moderate levels of fluoride continuous exposure can modify bone during long-term consumption, since high concentrations would cause either lethal heart block or heart muscle degeneration before such bone changes could eventually develop. First, no noticeable symptoms exist while bone is slowly converted to fluoroapatite. Stage III is characterized with inability to walk, likely due to the painful sharp spicules that would rub surrounding tissue.
The bones shown here were formerly displayed in the Bone Diseases of Man exhibit at the San Diego Museum of Man, Balboa Park, San Diego, CA.
Ironically, ingestion of treated water with 1 ppm fluoride does not reduce caries either systemically at ~0.15 ppm or topically from saliva at 0.016 ppm which is 95,000 times less concentrated than in toothpastes, completely ineffective in treating dental caries. Electron microscopic studies revealed that topical fluoride even at 12,000 ppm in dental gels applied to teeth merely forms calcium fluoride globules on surfaces that are readily washed away upon eating and are swallowed. The U.S. Food and Drug Administration has never approved fluoride compounds for ingestion in the U.S. The FDA has written that fluoride is not a mineral nutrient and has labeled fluoride in water an uncontrolled use of an unapproved drug. In 1966, the FDA banned the sale of all fluorides intended for ingestion by pregnant women The FDA ruled that fluoride is considered unsafe to add to foods.
The original correlation in 1939 of water fluoride and dental caries was mere scatter. No relationship existed between caries incidence and water fluoride concentration up to 6 ppm when all data are considered. Caries incidence in 5 year old children in New Zealand has been on the decline since the 1930’s, prior to the spread there of water fluoridation in the 1960’s and the later use of fluoridated toothpaste in the 1970’s. A most logical interpretation is that the invention of the nylon toothbrush in 1938 and its eventual spread worldwide is instead largely responsible for the effect. Declining caries incidence has been ongoing worldwide since the 1970’s in countries whether fluoridated or not and whether fluoridated salt is offered or not. Normal teeth enamel is a calcium phosphate matrix that does not contain fluoride. Research animals raised under controlled conditions in the complete absence of any fluoride source, either natural or synthetic, develop normal teeth enamel without increase in incidence of spontaneous dental caries.
These controlled experimental data carefully using the scientific method demonstrated in three separate laboratories that ingested fluoride is not a mineral nutrient. In another animal study, 1 ppm artificial fluoride in drinking water did not decrease incidence of spontaneous dental caries. Thus fluoride does not affect teeth caries by either a systemic mechanism after assimilation or by direct contact with teeth surfaces from either fluoridated saliva or from treated water in the tested animals. The largest U.S. epidemiologic studies we have found caries incidence does not correspond to fluoride water level. The largest international study we have indicates that caries incidence is lowest in cities with the lowest levels of water fluoride and with calcium-sufficient diets. The U.S. CDC published findings that systemic fluoride from swallowing does not affect caries.
In fact, systemic fluoride plays the most major role in causing the current U.S. high incidence of tooth fluorosis in children that prompted the U.S Health and Human Services to request in 2011 that added water fluoride be lowered from ~1 ppm to 0.7 ppm. This has not eliminated the problem, where 56% of U.S. teens now have significant unsightly abnormal dental enamel hypoplasia (fluorosis) in all treated cities.