1. A dentifrice composition containing cationically modified silicon dioxide in an amount effective to treat or prevent erosive damage to the enamel surface of the tooth. The composition of claim 1, wherein the cationically modified silica comprises silica covalently bonded to a positively charged amino acid. The composition of claim 2, wherein the positively charged amino acid is lysine. The composition of claim 1, wherein the cationically modified silica comprises silica covalently bonded to a positively charged peptide. The composition of claim 1, wherein the positively charged peptide is polylysine. The composition of claim 1, wherein the cationically modified silica comprises silica covalently bonded to silane. The composition of claim 1, wherein the silane comprises aminosilanes, glycidoxysilanes, mercaptosilanes, and combinations thereof. The composition of claim 1, wherein the aminosilane contains (3-aminopropyl) -triethoxysilane, (3-aminopropyl) -diethoxy-methylsilane, (3-aminopropyl) -dimethyl-ethoxysilane, and a combination thereof. The composition of claim 1, wherein the glycidoxysilane contains (3-glycidoxypropyl) dimethyl ethoxysilane. The composition of claim 1, wherein the mercaptosilane contains (3-mercaptopropyl) trimethoxysilane, (3-mercaptopropyl) methyl dimethoxysilane, and combinations thereof. The composition according to claim 1, where the amount of cationically modified silicon dioxide, effective to treat or prevent erosive damage to the enamel surface of the tooth, is from 0.01% of the mass. up to 30% of the mass. by weight of the composition. 12. The composition according to claim 1, where the amount of cationically modified silica is effective to treat or prevent this1. Композиция средства для ухода за зубами, содержащая катионномодифицированный диоксид кремния в количестве, эффективном для лечения или предотвращения эрозивного повреждения эмалевой поверхности зуба.2. Композиция по п.1, где катионномодифицированный диоксид кремния содержи
