An in Vitro and in Vivo Investigation of the Anti-caries Activity of Medium-chain Fatty Acids

Abstract

Fatty acids (FA)have been known to have a caries-protective effect for many years and show bactericidal and surface-active properties. This work was undertaken to compare the degree of caries protection offered by medium-chain FA with chain lengths of 9-12 carbons and to assess the anti-caries potential of sodium laurate, which showed the greatest anti-caries effect among the FA tested. The sodium salts of FA significantly reduced plaque bacterial metabolism by 7 standard strains of acidogenic bacteria in a dose-dependent manner and the order of bacterial metabolism reduction was from sodium laurate to decanoate to nonanoate. Because sodium laurate showed maximum anti-caries potential in vitro, we further examined directly its anti-caries effect using an in vivo rat model. Sodium laurate also produced a highly significant reduction in caries occurrence compared to that of control and gave a greater degree of caries prevention than fluoride in vivo. Our results indicate that the salt form of laurate has a very strong anti-caries effect in vitro and in vivo.