Dental products with casein phosphopeptide--amorphous calcium phosphate-nanocomplexes (CPP-ACP) are used in several tooth products (toothpastes, chewing gums, mouthrinses) and are as well used in dental filling material. CPP-ACP containing products are supposed to enhance remineralisation of dental hard tissues und thus might play a major role in prevention and therapy of initial caries or erosively dissolved enamel. Furthermore, also in hypersensitive teeth and even cases of hyposalivation, CPP-ACP containig products are supposed to improve the clinical condition. This article aims at three goals: point out the evolvement of CPP-ACP out of milk casein; description of possible biochemical effects of CPP-ACP on dental hard tissues; critical review of the current literature.