title: Curing efficiency of high-intensity light-emitting diode (LED) devices.
abstract: We evaluated the curing efficiency of 4 high-intensity light-emitting diode (LED) devices by assessing percentage of residual C=C (%RDB), surface microhardness (SM), depth of cure (DC), percentage of linear shrinkage-strain (%LS), and percentage of wall-to-wall contraction (%WWC). The light-curing units tested were a QTH light, the Elipar TriLight (3M/ESPE), and 4 LED devices - the Allegro (Denmat), the Bluephase (Ivoclar/Vivadent), the FreeLight2 (3M/ESPE), and The Cure TC-01 (Spring Health Products). The %RDB was measured by microFTIR spectroscopy. Microhardness measurements (Vickers) were performed at the surface (H0) and at depths of 3 mm (H3) and 5 mm (H5) of cylindrical specimens. Depth of cure was expressed as the ratio of microhardness at each depth, relative to the corresponding surface value (H3/H0 and H5/H0). The bonded disc method was used to evaluate %LS. For the %WWC evaluation, cylindrical resin restorations were imaged by high resolution micro-CT and the %WWC was calculated at depths of 0 mm and 2 mm. There were no statistical differences among the LEDs in %RDB or %LS. The Bluephase and Allegro had the highest SM values. As compared with the other LEDs, the Bluephase and The Cure TC-01 had lower values for depth of cure at depths of 3 mm and 5 mm. There were no significant differences in %WWC among the LEDs at either depth, and the QTH had the lowest %WWC at both depths.
authors.affiliation: Department of Oral Biology, Faculty of Dentistry, University of Athens, Goudi, Greece. craxioti@dent.uoa.gr
authors.forename: Christos
authors.initials: C
authors.lastname: Rahiotis
authors.forename: Katerina
authors.initials: K
authors.lastname: Patsouri
authors.forename: Nick
authors.initials: N
authors.lastname: Silikas
authors.forename: Afrodite
authors.initials: A
authors.lastname: Kakaboura
mesh_terms: D002244:Carbon / Q000737:chemistry / Q000528:radiation effects; D003188:Composite Resins / Q000737:chemistry* / Q000528:radiation effects; D055117:Curing Lights, Dental / Q000145:classification* / Q000592:standards; D018772:Dental Marginal Adaptation; D003764:Dental Materials / Q000737:chemistry* / Q000528:radiation effects; D006244:Hardness; D006801:Humans; D008422:Materials Testing; D055668:Photochemical Processes; D011108:Polymers / Q000737:chemistry / Q000528:radiation effects; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D055114:X-Ray Microtomography
chemical_list: D003188:Composite Resins; D003764:Dental Materials; D011108:Polymers; C467914:TPH spectrum; D002244:Carbon