Modelingg of the Viscoelastic Behavior of Dental Light-activatedd Resin Composites during Setting

t Thee aim of this study is to investigate three mechanical models to describe thee viscoelastic behavior of a commercially available light-activated restorative compositee during setting. Stress-strain data on Z100 were recorded by a dynamicc test method performed on a universal testing machine. The models weree tested by matching the model response to experimental data and the materiall parameters Young's modulus (E) and viscosity (r|) associated with the modell were calculated. The universal testing machine generated reliable stress-strainn data on the fast setting, light activated resin composite. The high polymerizationn rate of Z100 had a negative effect on the viscous flow capability off the material. Only a minor proportion of composite shrinkage failed to contributee to stress development in the composite. A predictive model of the viscoelasticc behavior of Z100 during setting was carried out, using the Maxwell modell for the initial 3 minutes in the setting process and the Kelvin model for the remainderr of the process.