title: Effect of dentin dehydration and composite resin polymerization mode on bond strength of two self-etch adhesives.
abstract: BACKGROUND
  Dual-cured composite resins are similar to self-cured composite resins in some of their clinical applications due to inadequate irradiation, lack of irradiation, or delayed irradiation. Therefore, incompatibility with self-etch adhesives (SEAs) should be taken into account with their use. On the other, the extent of dentin dehydration has a great role in the quality of adhesion of these resin materials to dentin. The aim of this study was to investigate the effect of dentin dehydration and composite resin polymerization mode on bond strength of two SEAs.
  
  
  METHODS
  A total of 120 dentinal specimens were prepared from extracted intact third molars. Half of the samples were dehydrated in ethanol with increasing concentrations. Then Clearfil SE Bond (CSEB) and Prompt L-Pop (PLP) adhesives were applied in the two groups. Cylindrical composite resin specimens were cured using three polymerization modes: (1) Immediate light-curing, (2) delayed light-curing after 20 min, and (3) self-curing. Bond strength was measured using universal testing machine at a crosshead speed of 1 mm/min. Data were analyzed with two-way ANOVA and Duncan post hoc tests. Statistical significance was defined at P < 0.05.
  
  
  RESULTS
  There were no significant differences for CSEB subgroups with hydrated and dehydrated dentin samples between the three different curing modes (P > 0.05). PLP showed significant differences between subgroups with the lowest bond strength in hydrated dentin with delayed light-curing and self-cured mode of polymerization.
  
  
  CONCLUSIONS
  Within the limitations of this study, a delay in composite resin light-curing or using chemically cured composite resin had a deleterious effect on dentin bond strength of single-step SEAs used in the study.
authors.affiliation: Department of Operative Dentistry, Dental Materials Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Pooran
authors.initials: P
authors.lastname: Samimi
authors.affiliation: Private Practice, Isfahan, Iran.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Alizadeh
authors.affiliation: Department of Orthodontics, Torabinejad Dental Research Center, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Farinaz
authors.initials: F
authors.lastname: Shirban
authors.affiliation: Private Practice, Isfahan, Iran.
authors.forename: Amin
authors.initials: A
authors.lastname: Davoodi
authors.affiliation: Department of Operative Dentistry, Dental Materials Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Khoroushi
keywords: Chemically cured; composite resins; dental adhesives; dental bonding; light-curing