Restorative & Materials · single question
What activates the chemical polymerization of acrylic resin (PMMA) dental prosthesis base?
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Correct answer: A. Tertiary amine (chemical activator)
A) Tertiary amine (chemical activator) — CORRECT for cold-cure/self-cure acrylic.
Self-curing (cold-cure) acrylic resin is activated by a TERTIARY AMINE (e.g., N,N-dimethyl-p-toluidine) which acts as a chemical activator that reacts with benzoyl peroxide (initiator) in the powder to generate free radicals and initiate polymerization at room temperature — no heat required. This is used in temporary crowns, repairs, reline materials.
B) Heat (thermopolymerization): Used for heat-cured acrylic (denture base acrylic) — different mechanism. The question asks specifically about chemical activation.
C) UV light: Used for some photopolymerizable materials but not traditional PMMA.
D) Benzoyl peroxide alone: Is the INITIATOR (in the powder component) but requires the tertiary amine to activate it at room temperature.
Self-curing (cold-cure) acrylic resin is activated by a TERTIARY AMINE (e.g., N,N-dimethyl-p-toluidine) which acts as a chemical activator that reacts with benzoyl peroxide (initiator) in the powder to generate free radicals and initiate polymerization at room temperature — no heat required. This is used in temporary crowns, repairs, reline materials.
B) Heat (thermopolymerization): Used for heat-cured acrylic (denture base acrylic) — different mechanism. The question asks specifically about chemical activation.
C) UV light: Used for some photopolymerizable materials but not traditional PMMA.
D) Benzoyl peroxide alone: Is the INITIATOR (in the powder component) but requires the tertiary amine to activate it at room temperature.
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