The invention relates to oral and dental care agents and dental cleaning agents comprising > 0.005 % by weight of calcium salt(s) in the form of individual crystallites or particles comprising a plurality of said crystallites, an individual crystallite having a thickness ranging between 2 and 50 nm and a length ranging between 10 and 150 nm. The particles are rod and/or plate-shaped, preferably predominantly plate-shaped and the agent has a viscosity, (after 7 days of storage at 20 °C, measured at 20 °C and an air pressure of 1 bar, Brookfield viscosimeter RVDV II+, with Helipath at a shear rate of 4 U/min), of 450,000 to 1,000,000 mPas, preferably from 500,000 to 700,000 mPas and in particular from 550,000 to 650,000 mPas. Said oral and dental care agents and dental cleaning agents remineralise the teeth, making them less sensitive to external influences.