Abstract: A precipitated silica which contains an active substance with a characteristic, delayed release of active substance is prepared by adding the active substance during preparation of the precipitated silica. The precipitated silica containing the active substance may be added to oral hygiene agents such as toothpastes, topical fluoride preparations, dental materials or medicinal chewing gums.

Abstract: A dentifrice consists of the customary known non-abrasive dentifrice components which contains cellulose powder instead of customary known polishing bodies as the abrasive component.

Abstract: The toothpaste for preventative oral hygiene contains a mixture of synthetically prepared precipitated silicic acid and perlite in addition to a solvent as cleaning body.A mixture consisting of glycerol (86%) and water is used as solvent.

Abstract: A dental-care composition having improved shelf life in respect of rheology and abrasiveness, which as a novel feature, contains, as a cleansing agent, a bifunctional (thickening and abrasive) precipitated silica characterized by the following physico-chemical properties:______________________________________ Pendulum roller mill Jet mill ______________________________________ BET surface area m.sup.2 /g 15-110 15-110 Tamped density g/l 150-750 90-650 Secondary particle size FIG. 1 FIG. 2 distribution according to Coulter Counter "ALPINE" screen % by <1.5 <0.1 retainings > 63 .mu.m weight Cu abrasion in 10% mg 5-30 5-30 strength glycerol disper- sion Lightness value A % 86-96 90-96 Viscosity in a 30% 30,000-60,000 30,000-60,000 strength dispersion in a 1:1 glycerol/water mixture, Brookfield RTV, Sp5 ______________________________________The dental-care composition may additionally contain 0.

Abstract: A dental-care composition having improved shelf life in respect of rheology and abrasiveness, which, as a novel feature, contains, as a cleansing agent, a bifunctional (thickening and abrasive) precipitated silica characterized by the following physico-chemical properties:______________________________________ Pendulum roller mill Jet mill ______________________________________ BET surface area m.sup.2 /g 15-110 15-110 Tamped density g/1 150-750 90-650 Secondary particle size FIG. 1 FIG. 2 distribution according to Coulter Counter "ALPINE" screen % by <1.5 <0.1 retainings >63 .mu.m weight Cu abrasion in 10% mg 5-30 5-30 strength glycerol disper- sion Lightness value A % 86-96 90-96 Viscosity in a 30% 30,000-60,000 30,000-60,000 strength dispersion in a 1:1 glycerol/water mixture, Brookfield RTV, Sp5 ______________________________________The dental-care composition may additionally contain 0.

Abstract: A dental-care composition having improved shelf life in respect of rheology and abrasiveness, which, as a novel feature, contains, as a cleansing agent, a bifunctional (thickening and abrasive) precipitated silica characterized by the following physico-chemical properties:______________________________________ Pendulum roller mill Jet mill ______________________________________ BET surface area m.sup.2 /g 15-110 15-110 Tamped density g/l 150-750 90-650 Secondary particle size FIG. 1 FIG. 2 distribution according to Coulter Counter "ALPINE" screen % by <1.5 <0.1 retainings > 63 .mu.m weight Cu abrasion in 10% mg 5-30 5-30 strength glycerol disper- sion Lightness value A % 86-96 90-96 Viscosity in a 30% 30,000-60,000 30,000-60,000 strength dispersion in a 1:1 glycerol/water mixture, Brookfield RTV, Sp5 ______________________________________The dental-care composition may additionally contain 0.

Abstract: A dental-care composition having improved shelf life in respect of rheology and abrasiveness, which, as a novel feature, contains, as a cleansing agent, a bifunctional (thickening and abrasive) precipitated silica characterized by the following physico-chemical properties:______________________________________ Pendulum roller mill Jet mill ______________________________________ BET surface area m.sup.2 /g 15-110 15-110 Tamped density g/l 150-750 90-650 Secondary particle size FIG. 1 FIG. 2 distribution according to Coulter Counter "ALPINE" screen % by <1.5 <0.1 retainings > 63 .mu.m weight Cu abrasion in 10% mg 5-30 5-30 strength glycerol dispersion Lightness value A % 86-96 90-96 Viscosity in a 30% 30,000-60,000 30,000-60,000 strength dispersion in a 1:1 glycerol/water mixture, Brookfield RTV, Sp 5 ______________________________________The dental-care composition may additionally contain 0.