PURPOSE: To produce the titled material effective to facilitate the manufacture of a denture base, by using a mixture of acrylic monomer and polymer as a raw material, adding a polymerization initiator and sensitizer reactive with visible light and ultraviolet ray to the material, and forming the obtained resin composition to a sheet having a specific thickness.

CONSTITUTION: An acrylic monomer is added to powdery acrylic polymer, and the obtained raw material is mixed with a polymerization initiator and sensitizer reactive with visible light and ultraviolet ray to start the polymerization, e.g. benzyl, α-naphthyl, camphorquinone, etc. The obtained photosetting resin having sufficient plasticity to follow the surface shape of a jaw model and to keep the shape after releasing from the model is formed to a sheet of 0.5W5.0mm thick. Since the material is supplied in the form of a sheet, it can be cured rapidly by light irradiation after preparing the individual tray or basement having satisfactory shape. When a hole of 0.5W3.0mm diameter is bored to the sheet, it is especially advantageous in the use of a nonsticking impression material such as silicone, etc.