title: Shear bond strength of three dual-cured resin cements to dentin analyzed by finite element analysis.
abstract: OBJECTIVE
  To determine the shear bond strength to bovine dentin of dual-cured resin cements cured in different circumstances, the contraction stress and volumetric shrinkage in both polymerization modes, and to review the failure stress distribution at the cement-tooth interface with finite element analysis.
  
  
  METHODS
  The volumetric shrinkage of RelyX Unicem, Panavia F 2.0 and DC Core Automix was determined by mercury dilatometry. Polymerization contraction stress was determined using a constraint tensilometer set-up. For the shear bond strength test, cement discs on bovine root dentin (self-cured and dual-cured), composite discs cemented to dentin (self-cured and dual-cured), and dentin cemented to dentin (self-cured) specimens were fabricated. Specimens were stored in water for 24h (37°C, 100% humidity) and tested (crosshead speed 1mmmin(-1)). FE modeling of the specimens was carried out in order to calculate the maximum shear stresses in the cement-dentin interface. Differences between groups were determined using two-way ANOVA with Tukey post hoc tests, and paired samples t-tests (α<0.05).
  
  
  RESULTS
  Panavia F2.0 showed significantly lower volumetric shrinkage than the other cements. Dual-curing lead to higher contraction stresses for all tested cements compared to self-curing. RelyX Unicem showed higher volumetric shrinkage when dual-cured. Shear bond strength and maximum shear stress was positively influenced by dual-curing. DC Core Automix performed best and Panavia F2.0 worst in terms of shear bond strength and maximum shear stress.
  
  
  CONCLUSIONS
  Curing mode may play an important role in the final bond strength to dentin of indirect restorations, depending on the material used.
authors: Department of Dental Materials Science, ACTA, University of Amsterdam and VU University Amsterdam, Gustav Mahlerlaan 3004, Amsterdam, The Netherlands. l.jongsma@acta.nl
authors: Leontine A
authors: LA
authors: Jongsma
authors: Niek
authors: N
authors: de Jager
authors: Cornelis J
authors: CJ
authors: Kleverlaan
authors: Prem
authors: P
authors: Pallav
authors: Albert J
authors: AJ
authors: Feilzer
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002417:Cattle; D003799:Dental Stress Analysis / Q000379:methods; D003804:Dentin / Q000737:chemistry*; D020342:Finite Element Analysis; D019279:Resin Cements / Q000737:chemistry*; D055116:Self-Curing of Dental Resins / Q000379:methods*; D033081:Shear Strength
chemical_list: D019279:Resin Cements