Pivotal research from the late 1950s continues to impact oral care technology development today. At that time, researchers at Indiana University successfully demonstrated the ability of fluoride to be incorporated into toothpaste and deliver an anticavity, or anticaries, benefit. The first toothpaste proven to be clinically effective against caries was the original Crest brand toothpaste, a product formulated with stannous fluoride (SnF2) in an abrasive system that was only partially compatible with the fluoride active. Earlier toothpastes had combined ionic sodium fluoride, a highly reactive species, with calcium-based abrasives such as calcium carbonate. The active anticaries agent, the F- ion, reacted with free calcium in these formulations, forming insoluble calcium flouride, which produced clinically ineffective products.
In the early 1960s, toothpastes formulated with other fluoride actives, sodium monofluorophosphate (SMFP) and amine fluoride were proven to be clinically effective. SMFP, a covalently bound form of fluoride, can be formulated with calcium abrasives since its reactivity is reduced in the formulation. In order to provide an anticavity benefit, SMFP must be hydrolyzed, generally from salivary enzymes, to release free fluoride. Note that amine fluoride, a fluoride/surfactant combination, is not available in the US market.
In the early 1980s, a fluoride-compatible silica system was perfected, enabling the delivery of high levels of bioavailable fluoride in clinically effective formulations. Today, the vast majority of toothpastes sold globally are formulated with one of these four clinically proven fluoride salts, i.e., sodium fluoride, amine fluoride, SMFP or stannous fluoride.