Effects of Cheese Extract and its Fractions on Enamel Demineralization in vitro and in vivo in Humans

Abstract

In order to isolate and identify the most active anti-cariogenic components(s) of aqueous cheese extract (CE), we separated it into low (LMW) (MW < 500), medium (MMW) (500 < MW < 10,000), and high (HMW) (MW > 10,000) molecular weight fractions by means of the Amicon ultrafiltration system. These fractions were then tested in vitro with a bacterial system containing S. mutans, adapted from that of Turtola (1977). The LMW fraction reduced the demineralization caused by the fermentation of sucrose by 96% (p <0.001) as compared with the water control; this was not significantly different from a 50% concentration of the CE. The MMW and HMW fractions reduced demineralization by 36 and 42%, respectively. The concentrations of acid-soluble calcium and phosphorus in CE, LMW, MMW, and HMW were 1509 and 462, 991 and 310, 231 and 7, and 162 and 3 μg/mL, respectively. A solution containing the same levels of calcium and phosphorus as CE was somewhat more effective in reducing demineralization in vitro than was CE itself (p <0.01). In vivo , the addition of these same calcium and phosphorus levels to a 10% sucrose solution reduced its cariogenicity by 67% (p <0.001), as judged by the intra-oral cariogenicity test (ICT). Plaque calcium and phosphorus concentrations were significantly higher in the ICT plaque samples subjected to the sucrose-Ca,P solution (p <0.01) than in the sucrose control. The resting pH, minimum pH, and shape of the pH curves produced by the sucrose control and sucrose-Ca,P were similar. These results indicate that most of the anti-cariogenic effect of cheese extract is due to its calcium and phosphorus content, which probably influences the demineralization-remineralization process.