Human vertebral bone: Relation of strength, porosity, and mineralization to fluoride content

Abstract

Radiographically normal vertebral bone cylinders from 80 male subjects were tested mechanicallly by static compression and analyzed for porosity, fluoride and ash content. As a group, they had low fluoride content, suggesting little prior intake, consonent with this geographic area. Nevertheless, increasing levels of fluoride were associated with bulkier bone, less porosity, and less mineral per unit of bone, which in direction though not degree suggested changes similar to those of osteomalacia and opposite from those of osteoporosis without apparent threshold. The higher fluoride hard tissue was weaker in static tests than that with less fluoride, but the increased bulk apparently offset this, resulting in bones of unchanged static strength. Hence, water fluoridation should not alter static bone strength. There has, however, been a recent report suggesting that increased mineralization of bone renders it more brittle and thus more likely to fracture on impact. Therefore, the possibility that fluoridation may increase impact resistance by lessening mineralization can be entertained.

Effect of Sodium Fluoride Administration to Rats on Bone Phosphorous Content and Phosphatemia

“…We have demonstrated that after 10 days of treatment with a daily oral dose of 40 µmol/100 g of body weight, bone mass of rats increases significantly [8]. The same results were obtained by others, but the quality of bone formed under fluoride administration is still matter of study [9]. Apart from the mentioned effects on bone, fluoride has effects on the secretion of insulin and in the homeostasis of glucose, both when administered as a single dose or in chronically treated rats [8,10].…”