Dynamic Viscoelasticity of Unpolymerized Light-Cured Composite Resin Reinforced with Retentive Filler and Clinical Manipulation Property / 医学研究杂志

ABSTRACT

Objective To evaluate the dynamic viscoelasticity of unpolymerized light-cured composite resins reinforced with retentive filler(RF)or normal filler(NF),and the effect of dynamic viscoelasticity on clinical manipulation.Methods The dynamic viscoelastic properties of two light-cured composite resins reinforced with RF or NF were measured respectively with the dynamic stress rheometer.Flowing property,filling capacity,shaping and stability were designed to describe the clinical manipulation of the composites.Results The dynamic viscoelastic behavior of the composites is sensitive to changes in frequency,composite resin reinforced with RF had significantly higher shear storage modulus(G')and shear loss modulus(G″)than composite resins reinforced with NF,and had significantly lower loss tangent(tan?).The former was found to be more viscous,and the latter was found to be more elastic.Clinically,composite resin reinforced with RF has a greater ability of stability and shaping,and a lower potential for deformation;composite resin reinforced with NF has a higher flowing ability,and with a good adaptation to the cavity of the tooth.Conclusions The ideal composites should have high G' and low tan?.