Abstract
Fluoride stimulates trabecular bone formation, whereas bisphosphonates reduce bone resorption and turnover. Fracture prevention has not been convincingly demonstrated for either treatment so far. We compared the effects of 1-yr treatment of 9-mo-old minipigs with sodium fluoride (NaF, 2 mg/kg/d p.o.) or alendronate (ALN, 4 amino-1-hydroxybutylidene bisphosphonate monosodium, 1 mg/kg/d p.o.) on the biomechanical and histomorphometric properties of pig bones. As expected, NaF increased and ALN decreased bone turnover, but in these normal animals neither changed mean bone volume. NaF reduced the strength of cancellous bone from the L4 vertebra, relative to control animals, and the stiffness (resistance to deformation) of the femora, relative to the ALN group. In the ALN-treated animals, there was a strong positive correlation between bone strength and L5 cancellous bone volume, but no such correlation was observed in the NaF group. Furthermore, the modulus (resistance to deformation of the tissue) was inversely related to NaF content and there was a relative decrease in bone strength above 0.25 mg NaF/g bone. Moreover, within the range of changes measured in this study, there was an inverse correlation between bone turnover, estimated as the percentage of osteoid surface, and modulus. These findings have relevant implications regarding the use of these agents for osteoporosis therapy.
-
-
Human vertebral bone: relation of strength, porosity, and mineralization to fluoride content
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,
-
Bone response to fluoride exposure is influenced by genetics
Genetic factors influence the effects of fluoride (F) on amelogenesis and bone homeostasis but the underlying molecular mechanisms remain undefined. A label-free proteomics approach was employed to identify and evaluate changes in bone protein expression in two mouse strains having different susceptibilities to develop dental fluorosis and to alter bone
-
In situ observation of fluoride-ion-induced hydroxyapatite-collagen detachment on bone fracture surfaces by atomic force microscopy
The topography of freshly fractured bovine and human bone surfaces was determined by the use of atomic force microscopy (AFM). Fracture surfaces from both kinds of samples exhibited complex landscapes formed by hydroxyapatite mineral platelets with lateral dimensions ranging from ~90 nm × 60 nm to ~20 nm × 20 nm. Novel AFM techniques
-
Cellular and histochemical characteristics of osteoid formed in experimental fluoride poisoning
The present study on the cellular and histochemical characteristics of osteoid formed in iliac crest bone during fluoride poisoning in rabbits was carried out as there is no information available to date either on its structural or biochemical characteristics. Osteoid formation in bone is prevalent both in fluorosis and in
-
Bone disease in hemodialysis patients with particular reference to the effect of fluoride
Forty-one patients on our chronic hemodialysis program were assessed for the degree of progression of bone disease over an average period of 46 months. Seven patients were using a fluoridated dialysate. Four of these seven patients developed a marked increase in osteoid as judged by bone biopsy, while in the
Related Studies :
-
-
-
Mechanisms by which fluoride may reduce bone strength
Based on a large body of animal and human research, it is now known that fluoride ingestion can reduce bone strength and increase the rate of fracture. There are several plausible mechanisms by which fluoride can reduce bone strength. As discussed below, these mechanisms include: Reduction in Cortical Bone Density De-bonding of
-
Skeletal Fluorosis Causes Bones to be Brittle & Prone to Fracture
It has been known since as the early as the 1930s that patients with skeletal fluorosis have bone that is more brittle and prone to fracture. More recently, however, researchers have found that fluoride can reduce bone strength before the onset of skeletal fluorosis. Included below are some of the
-
Skeletal Fluorosis: The Misdiagnosis Problem
It is a virtual certainty that there are individuals in the general population unknowingly suffering from some form of skeletal fluorosis as a result of a doctor's failure to consider fluoride as a cause of their symptoms. Proof that this is the case can be found in the following case reports of skeletal fluorosis written by doctors in the U.S. and other western countries. As can be seen, a consistent feature of these reports is that fluorosis patients--even those with crippling skeletal fluorosis--are misdiagnosed for years by multiple teams of doctors who routinely fail to consider fluoride as a possible cause of their disease.
-
Fluoride Exposure Increases Metabolic Requirement for Calcium & Vitamin D
It is well known that individuals with nutrient deficiencies are more susceptible to fluoride toxicity, including fluoride's bone effects. As discussed in the following studies, fluoride increases the skeleton's need for calcium (and vitamin D) by increasing the amount of unmineralized tissue (osteoid) in the bone. When insufficient calcium and
-
Fluoride Reduces Bone Strength Prior to Onset of Skeletal Fluorosis
The majority of animal studies investigating fluoride's impact on bone strength have found that fluoride has either no effect, or a detrimental effect, on bone strength. Importantly, several of the animal studies that have found fluoride reductes bone strength have reported that this reduction in strength occurs before signs of skeletal fluorosis
Related FAN Content :
-