Abstract: The present invention relates to a solid composition comprising: a calcium silicate powder, a set accelerator in the form of a powder, a reinforcing filler in a solid form, a radio-opacifying agent in a solid form, at least one complementary ingredient selected from solid fibers or solid porous fillers, optionally a water-reducing agent in a solid form, and optionally solid pigments. The present invention also relates to a kit of parts for the preparation of a composition suitable for use in dentistry comprising in a first container a solid phase including the solid composition according to the invention, and in a second container an aqueous phase. The present invention also relates to a kit of parts for the preparation of a composition suitable for use in dentistry comprising a container, said container comprising at least two cells, the first cell comprising a solid phase including the solid composition of the invention and the second cell comprising an aqueous phase.