title: Temperature Rise Induced by Light Curing Unit Can Shorten Enamel Acid-Etching Time.
abstract: OBJECTIVE
  The aim of this in-vitro study was to assess the thermal effect of light emitting diode (LED) light curing unit on the enamel etching time.
  
  
  METHODS
  Three treatment groups with 15 enamel specimens each were used in this study: G1: Fifteen seconds of etching, G2: Five seconds of etching, G3: Five seconds of etching plus LED light irradiation (simultaneously). The micro shear bond strength (μSBS) of composite resin to enamel was measured.
  
  
  RESULTS
  The mean μSBS values ± standard deviation were 51.28±2.35, 40.47±2.75 and 50.00±2.59 MPa in groups 1, 2 and 3, respectively. There was a significant difference between groups 1 and 2 (P=0.013) and between groups 2 and 3 (P=0.032) in this respect, while there was no difference between groups 1 and 3 (P=0.932).
  
  
  CONCLUSIONS
  Simultaneous application of phosphoric acid gel over enamel surface and light irradiation using a LED light curing unit decreased enamel etching time to five seconds without compromising the μSBS.
authors: Faculty Member, Department of Restorative Dentistry, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors: Ahmad
authors: A
authors: Najafi Abrandabadi
authors: Assistant Professor, Dental Research Center, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors: Seyedeh Mahsa
authors: SM
authors: Sheikh-Al-Eslamian
authors: Assistant Professor, Dental Research Center, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors: Narges
authors: N
authors: Panahandeh
keywords: Acid Etching, Dental; Curing Lights, Dental; Dental Enamel