title: Temperature rise induced by some light emitting diode and quartz-tungsten-halogen curing units.
abstract: Because of the risk of thermal damage to the pulp, the temperature rise induced by light-curing units should not be too high. LED (light emitting diode) curing units have the main part of their irradiation in the blue range and have been reported to generate less heat than QTH (quartz-tungsten-halogen) curing units. This study had two aims: first, to measure the temperature rise induced by ten LED and three QTH curing units; and, second, to relate the measured temperature rise to the power density of the curing units. The light-induced temperature rise was measured by means of a thermocouple embedded in a small cylinder of resin composite. The power density was measured by using a dental radiometer. For LED units, the temperature rise increased with increasing power density, in a statistically significant manner. Two of the three QTH curing units investigated resulted in a higher temperature rise than LED curing units of the same power density. Previous findings, that LED curing units induce less temperature rise than QTH units, does not hold true in general.
authors.affiliation: Department of Dental Materials, School of Dentistry, Faculty of Health Sciences, University of Copenhagen, 20 Norre Alle, DK-2000 Copenhagen N, Denmark. ea@odont.ku.dk
authors.forename: Erik
authors.initials: E
authors.lastname: Asmussen
authors.forename: Anne
authors.initials: A
authors.lastname: Peutzfeldt
mesh_terms: D003188:Composite Resins / Q000737:chemistry / Q000528:radiation effects; D004867:Equipment Design; D006801:Humans; D008029:Lighting / Q000295:instrumentation*; D008422:Materials Testing; D013696:Temperature; D013821:Thermometers
chemical_list: D003188:Composite Resins; C121818:Tetric ceram