The most commonly used denture base material, heat-cured acrylic resin (PMMA), is polymerized by which primary activation method?

Heat-cured acrylic resin (PMMA — polymethylmethacrylate) is the most widely used denture base material. Its polymerization is activated by heat: the benzoyl peroxide initiator in the powder is decomposed by elevated temperature (70-74°C water bath for 8+ hours, or a shorter cycle with boiling) to generate free radicals that initiate addition polymerization of the methyl methacrylate monomer. Heat-cured resins produce denser, more homogeneous polymers with fewer residual monomer problems compared to self-cured (autopolymerizing) resins. Self-cured (chemically activated) resins use an amine activator to decompose benzoyl peroxide at room temperature. Microwave-activated resins are an alternative but less commonly used in standard practice.