Photoinitiator
Pronunciation: foh-toh-ih-NIH-shee-ay-tor
A light-sensitive compound within a dental resin that, on exposure to a specific wavelength, generates free radicals to initiate polymerisation.
Full Definition
Photoinitiators are chemical species incorporated into light-cured dental materials—including composites, adhesives, and resin cements—that absorb photons at a characteristic wavelength and produce reactive free radicals, thereby triggering the polymerisation of resin monomers. Camphorquinone (CQ) is the most widely cited photoinitiator in dental literature, absorbing light in the blue region (~468 nm). Newer alternative photoinitiators such as Lucirin TPO are increasingly used in manuscripts discussing broad-spectrum or short-wavelength curing. Editors should verify consistent use of the term and confirm that activation wavelength data accompany any material characterisation claim.
Usage
Usage note: Distinguish from co-initiator: photoinitiators generate radicals directly on light absorption; co-initiators (e.g., amines) participate secondarily in the radical-generation reaction. Single word, no hyphen: 'photoinitiator'.
In Context
- "The manuscript specified camphorquinone as the photoinitiator activated by the LED curing unit at 468 nm." — Methods section, polymerisation kinetics study
- "Editors should flag any claim about curing depth that does not specify the photoinitiator concentration and light irradiance used." — Peer review checklist, dental materials journal