title: Modeling of the viscoelastic behavior of dental light-activated resin composites during curing.
abstract: OBJECTIVE
  Three models consisting of springs and dashpots were investigated to describe the viscoelastic behavior of a commercial light-activated restorative composite during curing.
  
  
  METHODS
  Stress-strain data on Z100 were recorded by means of a dynamic test method performed on a universal testing machine. The model was tested by matching its response to experimental data and the material parameters, E (Young's modulus) and eta (viscosity), associated with the model were calculated.
  
  
  RESULTS
  The universal testing machine generated reliable stress-strain data on the fast curing, light-activated resin composite during curing. The high polymerization rate of Z100 had a negative effect on the viscous flow capability of the material. A predictive model of the viscoelastic behavior of Z100 during curing was carried out, using the Maxwell model for the initial 3 min in the curing process and the Kelvin model for the remainder of the process.
  
  
  CONCLUSIONS
  Dental researchers analyzing shrinkage stress problems by mathematical modeling can obtain a good quantitative estimate of the shrinkage stress development of Z100 before the restoration is actually made.
authors.affiliation: Department of Dental Materials Science, Academic Centre of Dentistry Amsterdam (ACTA), Louwesweg 1, NL-1066 EA, Amsterdam, The Netherlands. b.dauvillier@acta.nl
authors.forename: Bibi S
authors.initials: BS
authors.lastname: Dauvillier
authors.forename: Maxim P
authors.initials: MP
authors.lastname: Aarnts
authors.forename: Albert J
authors.initials: AJ
authors.lastname: Feilzer
mesh_terms: D003188:Composite Resins / Q000737:chemistry* / Q000528:radiation effects*; D003793:Dental Restoration, Permanent; D003799:Dental Stress Analysis; D004548:Elasticity; D008027:Light; D008956:Models, Chemical; D012822:Silicon Dioxide / Q000737:chemistry / Q000528:radiation effects; D014783:Viscosity; D015040:Zirconium / Q000737:chemistry / Q000528:radiation effects
chemical_list: D003188:Composite Resins; C083568:Z100 composite resin; D012822:Silicon Dioxide; D015040:Zirconium