Over thirty years' research has failed to solve the controversy about use of fluoride in the treatment of osteoporosis. The marked increase of the mineral density of the bone in the lumbar spine is not unequivocally accompanied by a decrease of osteoporotic fractures. The therapeutic margin is narrow and there is no simple, validated method of dose adjustment. Consequently, fluoride should still be regarded as an experimental treatment, only to be used in the framework of clinical scientific research.