Scanning electron microscopic and electron microprobe X-ray analysis of cortical bone of fluoride-treated rabbits.

Sodium fluoride was administered to rabbits through the intragastric route at the rate of 10 mg/kg every day for a period of 8 months. Cortical bone from the diphyseal region of the femur was studied morphologically with a scanning electron microscope, and significant structural changes in collagen fiber were observed in the fluoride-treated animals as compared to normal bone. Similar bone samples were assessed physically for their CaK alpha/PK alpha ratio by electron microprobe x-ray analysis, and chemically for their calcium and phosphorus content. The bone from the rabbits to which sodium fluoride had been administered showed a higher Ca/P ratio than that from untreated control animals by both of the methods of assessment. Possible explanations for the increased Ca/P ratio in relation to the observed structural changes are discussed.