Rheologic properties of flowable, conventional hybrid, and condensable composite resins

Cited 0 time in webofscience Cited 0 time in scopus
Son, Ho-Hyun; Lee, In-Bog; Um, Chung-Moon
Issue Date
Dental Materials 2003;19:298-307
Complex viscosityCondensable compositeFlowable compositeViscoelasticFrequency domain phasor plot
Objectives. This research was undertaken to investigate the viscoelastic properties related to handling characteristics of five commercial flowable, two conventional hybrid and two condensable composite resins and to investigate the effect on the viscosity of filler volume fraction of composites.

Methods. A dynamic oscillatory shear test was used to evaluate the storage shear modulus (G′), loss shear modulus (G″), loss tangent (tan δ) and complex viscosity (η*) of the composite resins as a function of frequency (ω)—dynamic frequency sweep test from 0.01 to 100 rad/s at 25 °C—using an Advanced Rheometric Expansion System. To investigate the effect on the viscosity of the composites of the filler volume fraction, the filler weight% and filler volume% were measured by the Archimedes' principle using a pyknometer.

Results. The complex viscosity η* of flowable composites was lower than that of the hybrid composites and significant differences were observed between brands. The complex viscosity η* of condensable composites was higher than that of hybrid composites. The order of complex viscosity η* at ω=10 rad/s in order of decreasing viscosity was as follows, Synergy compact, P-60, Z-250, Z-100, Aeliteflo, Tetric flow, Compoglass flow, Flow it and Revolution. The complex viscosity of flowable composites, normalized with respect to Z-100, was 0.04–0.56 but Synergy compact was 2.158 times higher than that of Z-100. The patterns of the change of loss tangent (tan δ) of the composite resins with increasing frequency were significantly different between brands. Phase angles δ ranged from 30.9 to 78.1° at ω=10 rad/s. All composite resins exhibit pseudoplastic behavior with increasing shear rate. The relationships between the complex shear modulus G*, the phase angle δ, and the shear rate ω were represented by the frequency domain phasor form, G*(ω)=G* eiδ=G*δ. Only a weak relationship was found between filler volume% and the viscosity of the composite resins.

Significance. This investigation shows that the viscoelasticity of composites in the same class is significantly different between brands. This rheologic property of composite resins influences the handling characteristics of the materials. The locus of frequency domain phasor plots in a complex plane is a valuable method of representing the viscoelastic properties of composite resins.
Files in This Item:
There are no files associated with this item.
Appears in Collections:
College of Dentistry/School of Dentistry (치과대학/치의학대학원)Dept. of Dentistry (치의학과)Journal Papers (저널논문_치의학과)
  • mendeley

Items in S-Space are protected by copyright, with all rights reserved, unless otherwise indicated.