The effect of fluoride on the physical properties of the rat femur was investigated by using an Instron materials tester. Experimental animals consisting of 80 female weanling rats were employed. These were divided into two major groups of 40 rats each. Group I received adequate calcium in the diet and Group II received a low calcium (0.1%) diet. Group I and II were divided into five subgroups, the first subgroup being used as the control. Each of the other four subgroups was given a different dosage level of fluoride in their drinking water as follows: the second subgroup received Hereford, Texas, drinking water, which contains 3.4 ppm F; the third subgroup received 10.0 ppm F, as sodium fluoride, in deionized water; and the fifth subgroup received 45.0 ppm F, as sodium fluoride, in deionized water.

At 7 and 15 weeks the rats were x-rayed for the determination of bone density, the last x-ray being the time of sacrifice. The left and right femurs were removed, measured, and the shafts tested for strength and elasticity. The broken ends were photograph for volume and cortical thickness determination. In addition, the demur shafts were assayed for fluoride content.

From the tests made, the Load at the Elastic Limit, Maximum Load and Load at Breaking Point with their corresponding deflections were recorded. Using the above results, the Stress for each load, Energy Absorbed until breaking, Young's Modulus of Elasticity, Flexibility and Stiffness were calculated. An analysis of variance to determine the difference between means of the variables given above, within the five subgroups, was run. For the variables that showed significant differences between subgroups within major groups, t test were run to determine where and to what extent differences were found.

Comparing the results with the controls showed that the rats given an adequate calcium diet with 45.0 ppm F in their drinking water had a slight decrease in breaking strength, but a significantly greater flexibility. The rats given a low calcium diet with 10 ppm F and 45.0 ppm F in their drinking water showed a significant decrease in strength, but increased flexibility at the 10 ppm F level and a highly significant decrease in strength and reciprocal increase in flexibility at the 45.0 ppm F level. This last subgroup also showed a significant increase in the amount of energy absorbed. The results clearly show that, if calcium and the trace element fluorine, as sodium fluoride, are given in adequate, but not excessive amounts, they complement each other in improving the physical properties of bone.

LLU Discipline





Graduate School

First Advisor

Walter H. Roberts

Second Advisor

E. Harold Shryock

Third Advisor

U. D. Register

Fourth Advisor

Arthur E. Dalgleish

Fifth Advisor

William H. Taylor

Degree Name

Doctor of Philosophy (PhD)

Degree Level


Year Degree Awarded


Date (Title Page)




Library of Congress/MESH Subject Headings

Calcium, Dietary; Fluorides; Bone and Bones -- metabolism.



Page Count

vi; 61

Digital Format


Digital Publisher

Loma Linda University Libraries

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This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.


Loma Linda University Electronic Theses and Dissertations

Collection Website



Loma Linda University. Del E. Webb Memorial Library. University Archives

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