**5.7 Amorphous calcium phosphate of casein phosphopeptides**

Another material used for the remineralization of decalcifications on the enamel surface is casein phosphopeptide, which is obtained from the milk protein casein. The solution form, which is prepared by dissolving in water, acts by stabilizing calcium and phosphate ions.

In an alkaline medium, casein phosphopeptide combines with calcium phosphate to form CPP-ACP compound. Today, this compound is combined with fluorine ions and used as CPP-ACFP (casein phosphopeptide-amorphous calcium fluoride phosphate) [62].

Researchers working on the remineralization of fluorine and CPP-ACP have shown that toothpaste containing 2% CPP-ACP provides a similar remineralization amount to toothpaste containing 2800 ppm fluoride. In addition to 2% CPP-ACP, it was determined that the best results were obtained in the toothpaste with 1100 ppm fluoride added [63].

In a study, the higher amount of remineralization effect of CPP-ACP applied topically to the initial lesions for 14 days was visualized with an electron microscope, and it was found to be statistically significant [64].

In the study on the remineralization of initial enamel lesions, a 7% reduction in lesion depth was observed when toothpaste containing fluoride (1100 ppm) was applied alone, and a 10% reduction was observed when using toothpaste containing CPP-ACP. It was observed that there was a 13% reduction in lesion depth when toothpaste containing CPP-ACP was applied after the use of fluoridated toothpaste. Since casein is a milk protein, care should be taken in its use in patients with milk allergies [65].
