title: Light-emitting diode curing light irradiance and polymerization of resin-based composite.
abstract: BACKGROUND
  Light-emitting diode (LED) curing lights are becoming popular; however, questions about their efficiency remain. The authors performed a comprehensive analysis of the properties of resin-based composites cured with LED lights.
  
  
  METHODS
  The authors evaluated seven LED lights and one quartz-tungsten-halogen light (control). They measured intensity, depth of cure (DOC), degree of conversion (DC), hardness and temperature rise. They used three shades of a hybrid resin-based composite and a microfill composite, as well as one shade of another hybrid composite.
  
  
  RESULTS
  Two LED lights required additional cure time to reach a DOC similar to that of the control light. DC at the top of the samples was independent of the light used. At 2.0 millimeters, the DC for several LED lights was significantly lower than that for the control light and was correlated strongly to the light's intensity. The bottom-to-top ratio for hardness of resin-based composites cured by all but one light was greater than 0.80. All LED lights except one had smaller temperature rise than did the control light.
  
  
  CONCLUSIONS
  Six of the seven LED curing lights performed similarly to a quartz-tungsten-halogen curing light in curing resin-based composites. Clinical Implications. While LED curing lights and a quartz-tungsten-halogen light could cure resin-based composites, some resin-based composites cured with LED lights may require additional curing time or smaller increments of thickness.
authors.affiliation: Product Evaluations, Research and Laboratories, Division of Science, American Dental Association, 211 East Chicago Ave., Chicago, Ill 60611, USA. aravamudhank@ada.org
authors.forename: Krishna
authors.initials: K
authors.lastname: Aravamudhan
authors.forename: Cynthia J E
authors.initials: CJ
authors.lastname: Floyd
authors.forename: Duane
authors.initials: D
authors.lastname: Rakowski
authors.forename: Glenn
authors.initials: G
authors.lastname: Flaim
authors.forename: Sabine H
authors.initials: SH
authors.lastname: Dickens
authors.forename: Frederick C
authors.initials: FC
authors.lastname: Eichmiller
authors.forename: P L
authors.initials: PL
authors.lastname: Fan
mesh_terms: D003188:Composite Resins / Q000737:chemistry / Q000528:radiation effects*; D003764:Dental Materials / Q000737:chemistry / Q000528:radiation effects*; D004867:Equipment Design; D006244:Hardness; D006801:Humans; D008027:Light; D008029:Lighting / Q000295:instrumentation*; D008422:Materials Testing; D011108:Polymers / Q000737:chemistry / Q000528:radiation effects; D011829:Radiation Dosage; D013499:Surface Properties; D013696:Temperature
chemical_list: D003188:Composite Resins; D003764:Dental Materials; D011108:Polymers