RHEOLOGIC STUDY ON THE VISCOELASTIC PROPERTIES OF FLOWABLE AND CONDENSABLE RESIN COMPOSITES

The purpose of this investigation was to observe the viscoelastic properties of five commercial flowable(Aeliteflo, Flow it, Revolution, Tetric flow, Compoglass flow) , three conventional hybrid(Z-100,Z-250,P-60) and two condensable(Synergy compact, SureFil) resin composites. A dynamic oscillatory shear test was done to evaluate the storage shear' modulus (G' ) , loss shear modulus(G") , loss tangent(tan ) and complex viscosity(* ) of the resin composites as a function of frequency dynamic frequency sweep test from 0.01 to 100 rad/s at 25 - by using Advanced Rheometric Exparusion SystemtARES) . To investigate the effect On the viscosity of resin composites of filler volume fraction, the filler weight % and volume % were measured by means of Archimedes' principle using a pyknometer. The results were as follows 1.The complex viscosity * of flowable resins was lower than that of hybrid resins and significant differences were observed between brands. The complex viscosity * of condensable resins was higher than that of hybrid resins. The order of complex viscosity * at = 10 rad/s was as follows. Surefil, Synergy compact, P-60, Z-250, Z-100. Aeliteflo, Tetric flow, Compoglass flow, Flow it, Revolution. The relative complex viscosity of flowable resins compared to Z-100 was 0.04-0.56 but Surefil was 30.4 times higher than that of Z-100. 2.The storage shear modulus G' and the loss shear modulus G" of flowable resins were lower than those of hybrid resins but those of condensable resins were higher. The patterns of the change of loss tangent, tan of resin composites with increasing frequency were significantly different between brands.The phase angles,, ranged from 30.2-78.1at = 10 rad/s. 3.A11 composite resins represent pseudoplastic nature with increasing shear rate. 4.The complex shear modulus G* and the phase angle was represented by the frequency domain phaser form, G*( )= G* eI = G* . The locus Of frequency domain phaser plots in a complex plane was a valuable method that represent the viscoelastic properties of composite resins. 5.There was no direct linear correlationship but a weak positive relation was observed between filler volume % or weight % and the viscosity of the resin composites.보건복지부 보건의료기술연구개발