In the study above, less than 2 percent of calcium fluoride was absorbed and this was excreted quantitatively in the urine. No calcium fluoride was retained. But even calcium fluoride is not benign. The animals given calcium fluoride also developed mottled teeth - a clear sign that calcium fluoride could produce changes on the teeth merely by passing through the body, and not by being “stored in a tooth” or anywhere else.
In 1946 Samuel Chase, one of the authors of the above study, became president of the International Association for Dental Research (IADR). This organization promoted the idea that only the “fluoride ion” in the various fluoridation compounds was of importance. Yet he well knew that other fluorides did not behave like calcium fluoride - the “natural fluoride”, as can be seen in the above table. Unlike calcium fluoride, sodium fluoride was retained in great amounts in the body and was very toxic - as all findings indicated. Rock phosphate and sodium fluosilicate experiments yielded the same information.