A dentifrice, such as toothpaste, containing chitosan or pharmaceutically acceptable acid addition salt thereof with fluoride ions, for use against erosive tooth demineralization, and kits containing chitosan or pharmaceutically acceptable acid addition salt thereof with fluoride ions, wherein one of the two active agents is comprised in a dentifrice, are described. The dentifrice in the form of toothpaste may furthermore comprise dissolved tin, in particular stannous ions. Toothpastes containing chitosan or pharmaceutically acceptable acid addition salt thereof with fluoride ions are tested in the treatment or prevention of erosive tooth demineralisation caused by citric acid.
