title: The effect of photoactivation time and light tip distance on the degree of conversion of light and dual-cured dentin adhesives.
abstract: BACKGROUND
  The degree of conversion of dental adhesive is an important parameter since poor mechanical properties are related to low percentage of monomer-to-polymer conversion within resin-based materials.
  
  
  OBJECTIVE
  To evaluate the influence of polymerization time and light guide distance on the degree of conversion (DC) of three contemporary dental adhesives.
  
  
  METHODS
  The spectral data of ExciTE DSC, Single Bond ® , and Adper ® Prompt L-Pop were analyzed using FTIR spectroscopy after 20 s, 40 s, and 60 s of photoactivation times. Light tip distances were kept at 1, 3, and 6 mm during the exposures.
  
  
  METHODS
  Data were analyzed using ANOVA and Tukey's test (α = 0.05).
  
  
  RESULTS
  Within groups, greater DC values were found using a tip distance of 1 mm or a 60-s curing time for Single Bond ® (59%) and Adper ® Prompt L-Pop (65%). No statistically significant difference (P > 0.05) was found using either 1 mm or 3 mm tip distances after 20 s, 40 s, and 60 s of light curing time for Single Bond ® . ExciTE ® DSC showed the greatest DC values with light tip distances of 1 mm (90%) and 3 mm (89%), using 60 s of light curing.
  
  
  CONCLUSIONS
  The self-etch adhesive Adper ® Prompt L-Pop could be applied in shallow cavity preparations and must be light cured for at least 40 s. The light-cured total-etch adhesive ExciTE ® DSC could be applied in every restorative scenario if the curing time is extended up to 60 s or if the tip distance is extended up to 3 mm.
authors: Department of Operative Dentistry, Mashhad Dental School and Dental Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
authors: Fatemeh
authors: F
authors: Maleknejad
authors: Hamideh
authors: H
authors: Ameri
authors: Safa
authors: S
authors: Manafi
authors: Joseph
authors: J
authors: Chasteen
authors: Marjaneh
authors: M
authors: Ghavamnasiri
mesh_terms: D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry / Q000528:radiation effects; D055117:Curing Lights, Dental; D017220:Dentin-Bonding Agents / Q000737:chemistry* / Q000528:radiation effects; D006801:Humans; D055115:Light-Curing of Dental Adhesives / Q000295:instrumentation / Q000379:methods*; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry / Q000528:radiation effects; D058105:Polymerization; D011829:Radiation Dosage; D019279:Resin Cements / Q000737:chemistry / Q000528:radiation effects; D055116:Self-Curing of Dental Resins / Q000295:instrumentation / Q000379:methods*; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D013997:Time Factors
chemical_list: D017220:Dentin-Bonding Agents; C420130:Excite cement; D008689:Methacrylates; C408584:Prompt L-Pop; D019279:Resin Cements; C115612:single bond; D017438:Bisphenol A-Glycidyl Methacrylate