Which item is listed as a photoinitiator used in light-cured composites in the provided material?

Which item is listed as a photoinitiator used in light-cured composites in the provided material?

• A. HEMA
• B. Bis-GMA
• C. Photoinitiator
• D. Camphorquinone

Answer: (D)

A photoinitiator is the component in light-cured composites that absorbs light and generates reactive species to start polymerization. Camphorquinone is the classic photoinitiator used in many dental composites; when blue light around 470 nm shines on it, camphorquinone works with a co-initiator amine to form free radicals that kick off the polymerization of the methacrylate monomers in the resin. HEMA and Bis-GMA are monomers forming the resin matrix, not initiators, so they don’t initiate curing. Saying “photoinitiator” is too generic, whereas camphorquinone is the specific chemical commonly used for this purpose.

A photoinitiator is the component in light-cured composites that absorbs light and generates reactive species to start polymerization. Camphorquinone is the classic photoinitiator used in many dental composites; when blue light around 470 nm shines on it, camphorquinone works with a co-initiator amine to form free radicals that kick off the polymerization of the methacrylate monomers in the resin. HEMA and Bis-GMA are monomers forming the resin matrix, not initiators, so they don’t initiate curing. Saying “photoinitiator” is too generic, whereas camphorquinone is the specific chemical commonly used for this purpose.