title: Effect of various curing lights on the degree of cure of orthodontic adhesives.
abstract: BACKGROUND
  The purpose of this study was to compare the percentage degree of cure (%DC) of orthodontic adhesive resins irradiated with 3 types of light sources of various intensities: plasma arc, halogen, and light-emitting diode (LED).
  
  
  METHODS
  Twenty maxillary incisor stainless steel brackets (0.018-in slot) were divided into 4 groups of 5 brackets each. A standardized amount of composite resin was applied to each bracket base, simulating its clinical application. The brackets were light-cured with a halogen light for 20 seconds (10 seconds each from the incisal and cervical bracket edges), an LED light for 20 seconds (10 seconds per edge), a plasma light for 10 seconds (5 seconds per edge), and an LED light for 10 seconds (5 seconds per edge). The %DC was assessed by using micro-multiple internal reflectance Fourier transform infrared spectroscopy, and the results were analyzed with 1-way ANOVA.
  
  
  RESULTS
  Overall, the LED and the halogen lights, with the 20-second regimen, produced higher %DC. No significant difference was found in %DC between the plasma light and the 10-second LED light, whereas both showed lower %DC compared with 20 seconds of halogen or LED light.
  
  
  CONCLUSIONS
  Significant variations in %DC are associated with the various light-curing units, which must be considered in selecting the light source and the irradiation time.
authors.affiliation: Department of Developmental Sciences, Marquette University School of Dentistry, Milwaukee, Wis 53233, USA.
authors.forename: Markus
authors.initials: M
authors.lastname: Niepraschk
authors.forename: Christos
authors.initials: C
authors.lastname: Rahiotis
authors.forename: T Gerard
authors.initials: TG
authors.lastname: Bradley
authors.forename: Theodore
authors.initials: T
authors.lastname: Eliades
authors.forename: George
authors.initials: G
authors.lastname: Eliades
mesh_terms: D000704:Analysis of Variance; D001840:Dental Bonding; D003748:Dental Equipment; D003799:Dental Stress Analysis; D006219:Halogens; D008027:Light; D009967:Orthodontic Appliances; D044367:Phase Transition; D019279:Resin Cements / Q000528:radiation effects*; D012666:Semiconductors; D017550:Spectroscopy, Fourier Transform Infrared; D014978:Xenon