Composite Photoinitiator — MFDS Part 1 MCQ

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ModerateDental MaterialsComposite PhotoinitiatorMFDS Part 1

A conventional visible-light-cured resin composite contains several components with different functions. Which component primarily absorbs blue light and, after interaction with an amine co-initiator, leads to formation of the free radicals that start polymerisation?

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Correct answer: E — Camphorquinone

Camphorquinone is the conventional photoinitiator in many visible-light-cured resin composites. It absorbs blue light, particularly around 470 nm, and enters an excited state. Interaction with an amine co-initiator then produces free radicals, which initiate polymerisation of the methacrylate monomers. The silane coupling agent bonds the inorganic filler to the resin matrix, while filler particles provide reinforcement and modify handling and optical properties. Butylated hydroxytoluene is an inhibitor that limits premature polymerisation during storage. Triethylene glycol dimethacrylate is a low-viscosity diluent monomer that participates in polymer network formation but does not function as the photoinitiator.

Reference: Watts DC. Light-curing dental resin-based composites: How it works and how you can make it work. Frontiers in Dental Medicine. 2023. https://pubmed.ncbi.nlm.nih.gov/39916906/