In contrast, recent studies analysed the effects of products containing casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on erosion, as it is suggested that CPP-ACP promotes a supersaturated state and increased remineralisation of demineralised dental hard tissue. However, in situ studies on the effect of CPP-ACP on erosion are limited to one study, which compared microhardness of enamel after treatment with CPP-ACP and CPP-ACP and 900 ppm fluoride, but failed to use appropriate controls in form of other products containing calcium and phosphate or fluoride. In summary, the effects of milk, in particular fluoridated milk, and products containing milk proteins, such as casein phosphopeptide-amorphous calcium phosphate, on erosive wear were not analysed in an in-situ-model so far.