title: A novel polyurethane-based root canal-obturation material and urethane acrylate-based root canal sealer--part I: synthesis and evaluation of mechanical and thermal properties.
abstract: Resilon (RealSeal; SybronEndo, Orange, CA) has been developed as an alternative to gutta percha, but its advantages over gutta percha remain controversial. In this study, we developed a novel zinc oxide/thermoplastic polyurethane (ZnO/TPU) composite root canal-filling material and a visible-light curable urethane-acrylate/tripropylene glycol diacrylate (UA/TPGDA) root canal sealer. The mechanical and thermal properties of the ZnO/TPU composite were compared with those of gutta percha and Resilon. Results showed that the tensile strength and elastic modulus of the ZnO/TPU composite were markedly higher than those of gutta percha and Resilon. The melting points of all three materials were similar; however, the enthalpy change and specific heat of ZnO/TPU (9.4 J/g, 0.7 J/g degrees C) were close to those of gutta percha (10.9 J/g, 0.7 J/g degrees C) but lower than those of Resilon (28.9 J/g, 1.3 J/g degrees C). The results indicate that ZnO/TPU composite exhibits better mechanical strength than Resilon, and its combination with UA/TPGDA sealer has excellent potential to be used as a root canal-filling material.
authors.affiliation: Institute of Polymer Science and Engineering, National Taiwan University, Taipei, Taiwan.
authors.forename: Kuo-Huang
authors.initials: KH
authors.lastname: Hsieh
authors.forename: Ken-Hsuan
authors.initials: KH
authors.lastname: Liao
authors.forename: Eddie Hsiang-Hua
authors.initials: EH
authors.lastname: Lai
authors.forename: Bor-Shiunn
authors.initials: BS
authors.lastname: Lee
authors.forename: Chung-Yi
authors.initials: CY
authors.lastname: Lee
authors.forename: Chun-Pin
authors.initials: CP
authors.lastname: Lin
mesh_terms: D000180:Acrylic Resins; D003799:Dental Stress Analysis; D004548:Elasticity; D006171:Gutta-Percha; D008422:Materials Testing; D011140:Polyurethanes; D012387:Root Canal Filling Materials / Q000138:chemical synthesis* / Q000737:chemistry*; D012389:Root Canal Obturation / Q000379:methods*; D013718:Tensile Strength; D013816:Thermodynamics; D015034:Zinc Oxide
chemical_list: D000180:Acrylic Resins; D011140:Polyurethanes; D012387:Root Canal Filling Materials; C486892:resilon sealer; C050845:urethane acrylate; D006171:Gutta-Percha; D015034:Zinc Oxide