Solid, biocompatible and biodegradable amorphous calcium polyphosphate microparticles that (i) form a tightly bound polyphosphate layer onto the hydroxyapatite surface, (ii) have a hardness and elastic modulus close to natural enamel, (iii) are able to trigger differentiation of precursor cells into odontoblasts, and (iv) activate the expression of alkaline phosphatase in precursor odontoblasts, for use in sealing dentinal tubules exposed at the tooth surface and filling defects in tooth enamel, cementum and dentin, is provided. Preferably the amorphous calcium polyphosphate microparticles ameliorate dental hypersensitivity or are for the prophylaxis of dental caries. A tooth implant material that stimulates differentiation and activation of odontoblast precursor cells and odontoblasts wherein the material comprises amorphous calcium polyphosphate microparticles is outlined. A method for producing a toothpaste that stimulates differentiation and activation of odontoblast precursor cells and odontoblasts and/or for resealing dentinal tubules to ameliorate hypersensitivity wherein the toothpaste comprises amorphous calcium polyphosphate microparticles is also provided.
