Complex Fluorides: Caries Reduction and Fluorine Retention in the Bones and Teeth of White Rats

This study was made to obtain data on the physiological availab)ility and effects of fluorine as it occurs in several complex chemical combinations.The criteria for evaluation of these fluorides (as ad- ministered by injection and in drinking water of growing rats) were (1) deposition of fluorine in bones and teeth, (2) development of incisor striations and, (3) ability to inhibit experimental rat caries.These and similar experiments not only help to elucidate the metabolism of fluorine but may also have a practical application to fluoridation of drinking water, which has become an effective procedure for the partial control of human dental caries.Although sodium fluoride (NaF) is now the most common fluoride in use for community water fluoridation, other compounds, particularly sodium fluosilicate (Na2SiF6), if found comparable to NaF in physiological effects, may have an advantage in being produced at less expense than NaF.1In a previous publication (1) the junior author reviewed earlier reports of the effects of a number of different fluorides (NaF, Na2SiF6, Na3AIF6, BaSiF6, NH4F, KF, K2SiF6, and CaF2) and reported that NaF and Na2SiF6, when ingested in drinking water by growing rats in amounts which furnished 5, 10, 15, 25, and 50 ppm of fluorine, re- stilted in equivalent retentions of fluorine in the bones and teeth, mandibles, and femurs, and produced similar incisor striations.In general, this study (1) indicated that fluorine in NaF and Na2SiF6 is equally available.Deposition of fluorine in dental and skeletal tissues of hamsters receiving Na3AlF6, Na2PO3F, KPF6, NaF, and "Flural" 2 (2) was also recently reported.Less fluorine was retained in the lower incisors of hamsters receiving "Flural", KPF6, and Na3AlF8, than in hamsters *National Institute of Dental Research, Bethesda, Md.I Since commercial grade NaF is 95 percent pure, and at current market quotations (21) sells for 110 per lb., and commercial Na25iFe is 98 percent pure and sells for 50 per lb., the cost per lb. of available fluorine is now approximately three times more for NaF than for Na2SiF6.I Flural Is a commercial preparation of the Ozark-Mahoning Company, Tulsa, Okla., containing alum and a fluoride.One commercial grade has a composition approximating the formula AIFSO4.2H20(6).z 1 Q o .0'z ..