A novel polyurethane-based root canal obturation material:push-out bond strength

Objectives: In this study, we developed a novel zinc oxide/thermoplastic polyurethane (ZnO/TPU) composite root canal filling material and visible-light curable urethane-acrylate/tripropylene glycol diacrylate (UA/TPGDA) root canal sealer. Methods: The mechanical and thermal properties of the ZnO/TPU composite were compared with those of gutta-percha and Resilon. Results: 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/goC) were close to those of gutta-percha (10.9 J/g, 0.7 J/goC) but lower than those of Resilon (28.9 J/g, 1.3 J/goC). Conclusions: The results indicates 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.