title: Thermal emission and curing efficiency of LED and halogen curing lights.
abstract: The purpose of this study was to compare the thermal emission and curing efficiency of LED (LEDemetron 1, SDS/Kerr) and QTH (VIP, BISCO) curing lights at maximum output and similar power, power density and energy density using the same light guide. Also, another LED curing light (Allegro, Den-Mat) and the QTH light at reduced power density were tested for comparison. Increase in temperature from the tips of the light guides was measured at 0 and 5 mm in air (23 degrees C) using a temperature probe (Fluke Corp). Pulpal temperature increase was measured using a digital thermometer (Omega Co) and a K-type thermocouple placed on the central pulpal roof of human molars with a Class I occlusal preparation. Measurements were made over 90 seconds with an initial light activation of 40 seconds. To test curing efficiency, resin composites (Z100, A110, 3M/ESPE) were placed in a 2-mm deep and 8-mm wide plastic mold and cured with the LED and QTH curing lights at 1- and 5-mm curing distances. Knoop Hardness Numbers (KHN) were determiped on the top and bottom surfaces (Leco). Bottom hardness values were expressed as a percentage of maximum top hardness. No significant differences were found in maximum thermal emission or KHN ratios between the LED (LEDemetron 1) and the QTH (VIP) at maximum output and similar energy densities (ANOVA/Tukey's; alpha=0.05).
authors.affiliation: Dental Materials Evaluation, USAF Dental Investigation Service, Great Lakes, IL, USA. kraig.vandewalle@ndri.med.navy.mil
authors.forename: Kraig S
authors.initials: KS
authors.lastname: Vandewalle
authors.forename: Howard W
authors.initials: HW
authors.lastname: Roberts
authors.forename: Amer
authors.initials: A
authors.lastname: Tiba
authors.forename: David G
authors.initials: DG
authors.lastname: Charlton
mesh_terms: D001831:Body Temperature / Q000502:physiology; D003188:Composite Resins / Q000737:chemistry* / Q000528:radiation effects; D003782:Dental Pulp / Q000502:physiology; D003793:Dental Restoration, Permanent / Q000295:instrumentation*; D004867:Equipment Design; D006244:Hardness; D006358:Hot Temperature; D006801:Humans; D008027:Light; D008029:Lighting / Q000295:instrumentation*; D008422:Materials Testing; D012822:Silicon Dioxide / Q000737:chemistry / Q000528:radiation effects; D013696:Temperature; D013821:Thermometers; D015040:Zirconium / Q000737:chemistry / Q000528:radiation effects
chemical_list: D003188:Composite Resins; C452225:Filtek A110 composite resin; C083568:Z100 composite resin; D012822:Silicon Dioxide; D015040:Zirconium