Fluoride Action Network


In three different areas of Finland, fluoride in bone and its effect on the histomorphometry of trabecular bone was studied. Bone samples were taken from cadavers from a low-fluoride area (fluoride concentration under 0.3 ppm), an area with fluoridated drinking water (1.0-1.2 ppm) and a high-fluoride area (over 1.5 ppm). The fluoride content in trabecular bone was greatly increased in the high-fluoride area, and it was also higher in the fluoridated-water area than in the low-fluoride area. Histomorphometric bone changes were markedly increased when the fluoride content in water exceeded 1.5 ppm.


The main histolological change induced by fluoride is the increase of osteoid volume… This increase in osteoid parameters was observed in our study already at fluoride concentrations above 1.5 ppm. . . .  Fluoridation of drinking water up to 1.2 ppm apparently does not pose a potential risk to bone provided the renal function is normal. . . . We should, however, recognize that it is difficult to give a strict value for a safe fluoride concentration in drinking water, because individual susceptibility to fluoride varies.