The invention is directed to a powder composition for air polishing the surface of hard dental tissue comprising a powder of water-soluble organic particles as component A, a powder of inorganic anti-caking agent(s) particles as component B and a powder of antihypersensitive acting particles as component C, the mean particle size of component A being in a range from about 15 to about 500 μm, the mean particle size of component C being in a range from about 0.5 to about 10 μm. The invention is also directed to a kit of parts comprising the powder composition and its use.