A computer-implemented method of generating a 3D model for dental simulation, comprising reading a file describing the surface of a 3D object having a volume; generating a voxel grid encompassing the 3D object, wherein the voxel grid contains a plurality of voxels; identifying a subset of voxels of the plurality of voxels which are located within the volume of the 3D object; generating a triangulated surface, wherein the triangulated surface encompasses the subset of voxels and defines the outer surface of the 3D model; assigning a density value to each voxel in the subset of voxels, wherein the subset of voxels defines the solid volume of the 3D model.