What is the most commonly used base material for fabricating acrylic removable partial dentures (RPDs)?

Heat-cured (heat-polymerized) polymethyl methacrylate (PMMA) acrylic resin is the standard and most widely used material for fabricating the denture base of removable partial and complete dentures. Heat curing produces superior physical properties including greater strength, hardness, dimensional accuracy, and resistance to deformation compared to self-cure (cold-cure) acrylic. Self-cure acrylic is used chairside for temporary restorations, relines, and repairs due to its ease of use, but it has higher residual monomer content and inferior mechanical properties.