title: Dynamic viscoelastic behavior of dental composites measured by Split Hopkinson pressure bar.
abstract: The present study evaluated the dynamic viscoelastic behavior of commercially available dental composites by a Split Hopkinson pressure bar (SHPB) test machine. Five commercially available composite resins--namely, two conventional hybrid composites (Filtek Z100, Z100; Filtek Z250, Z250), a packable composite (Filtek P60, P60), a flowable composite (Filtek Flow, FL), and a nanofill composite (Filtek Supreme, SU)--were evaluated. By means of SHPB technique, the dynamic stress-strain curve, storage modulus, and loss tangent of the five dental composites were calculated. All specimens exhibited a nonlinear stress-strain curve in the loading process, which resulted not only from the viscoelasticity--but also from the plasticity--of matrix. In terms of storage modulus, no significant differences were exhibited among the five dental composites (p > 0.05). In terms of loss tangent, Z100 showed a significantly higher value than P60, FL, and SU (p < 0.05). Within the limitations of this investigation using SHPB, it was indicated that the loss tangent increased with increasing filler content.
authors.affiliation: Department of Dental Biomaterials, Research Institute of Oral Science, Nihon University School of Dentistry at Matsudo, 2-870-1, Sakaecho Nishi, Matsudo, Chiba 271-8587, Japan. tanimoto.yasuhiro@nihon-u.ac.jp
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Tanimoto
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Nishiwaki
authors.forename: Kimiya
authors.initials: K
authors.lastname: Nemoto
mesh_terms: D003188:Composite Resins / Q000737:chemistry; D003799:Dental Stress Analysis / Q000295:instrumentation; D004548:Elasticity; D008422:Materials Testing / Q000295:instrumentation; D010316:Particle Size; D014783:Viscosity
chemical_list: D003188:Composite Resins