The preferred material for repair of fractured denture base is:

REPAIR OF ACRYLIC RESIN DENTURES An acrylic denture fractured in service can be repaired. Repair resins maybe: Heat cure (OR) Self cure Heat cured resin These resins are cured at 74oC for 8 hours or more. The use of a heat-cured resin will tend to warp the denture during processing. Self-cured resin Although the repair with a self-cured resin invariably has a lower transverse strength than that of the original heat-cured denture base resin, self-cured resins are usually preferred because warpage is insignificant as curing is done at room temperature. Reference: Mannapallil Basic SCIENCE OF DENTAL MATERIALS, 4th ed page no 561