Multilayer-color composite material for use in dental department, and preparation method therefor

A method for preparing a multilayer-colored dental composite material, comprising:

• a) preparing N monochrome composite precursor powders with different colors, N≥3;
• wherein, the preparation process for each of the monochrome composite precursor powders comprises:
• mixing a polymer monomer matrix, an inorganic filler, an initiator, a coloring agent, and a milling additive, and milling for 0.5-2 h, then drying to obtain a monochrome composite precursor powder;
• wherein, the weight ratio of the polymer monomer matrix to the inorganic filler is 10:90-90:10, the initiator is 0.1%-1% by weight of the polymer monomer matrix, and the coloring agent is 0.01%-0.2% by weight, based on the total weight of the polymer monomer matrix and the inorganic filler;
• b) adding one monochrome composite precursor powder into a dry-pressing mould, and then adding another monochrome composite precursor powder into the dry-pressing mould successively after planishing the previously added powder, until the N monochrome composite precursor powders with different colors are all added into the dry-pressing mould;
• then pre-moulding by dry-pressing at a pressure of 3-20 MPa to obtain a pre-moulding green body of multilayer-colored composite material;
• or
• b′) performing a first pre-moulding by dry-pressing at a pressure of 3-20 MPa on the N monochrome composite material precursor powders, respectively, to obtain N monochrome pre-moulding green bodies;
• then adding all of the N monochrome pre-moulding green bodies into the mould successively, and performing a second pre-moulding by dry-pressing at the pressure of 3-20 MPa to obtain a pre-moulding green body of multilayer-colored composite material;
• c) pressurizing and heating the pre-moulding green body of multilayer-colored composite material prepared in step b) or b′) to obtain the multilayer-colored dental composite material, wherein, the pressurizing and heating is performed at a temperature of 100-200° C.