[Loss of trabecular bone strength and bone quality after 5 years of fluoride therapy for osteoporosis].

In order to evaluate the effect of sodium fluoride (NaF) on bone biomechanical competence, iliac crest biopsies were taken before and after one year of treatment in 12 osteoporotic patients, and before and after five years of treatment in 14 patients. Bone fluoride content had increased significantly after both one and five years of treatment, indicating that the administered fluoride had been ingested. After one year of treatment, no difference was observed in iliac crest trabecular bone ash content. A general trend for decreased bone strength and bone quality was observed, but this was insignificant. After five years of fluoride treatment, an insignificant decrease in iliac crest trabecular bone ash content was observed. A significant reduction of 45% was found in trabecular bone strength (p < 0.05), and an even more pronounced reduction of 58% was found in trabecular bone quality (p < 0.01). The results of this study indicate that long-term administration of sodium fluoride may be detrimental to bone quality, at least as measured in non-loaded iliac crest trabecular bone.