A Novel Polyurethane-Based Root Canal-Obturation Material and Urethane- Acrylate-Based Root Canal Sealer - Part 2: Evaluation of Push-out Bond Strengths

We have developed a visible-light curable urethaneacrylate/ tripropylene glycol diacrylate (UA/TPGDA) oligomer to serve as a root canal sealer and a zinc oxide/thermoplastic polyurethane (ZnO/TPU) composite to serve as a root canal obturation material. The purpose of this study was to compare the push-out bond strengths of the following 8 groups of materials: (1) Tubliseal + gutta-percha (TB/GP); ( 2) Tubliseal + Resilon (TB/R); (3) Epiphany + gutta-percha ( EP/GP); (4) Epiphany + Resilon (EP/R); (5) EndoREZ sealer + EndoREZ cone (ES/EC) (6) EndoREZ sealer + ZnO/TPU (ES/PU) ; ( 7) UA/TPGDA + EndoREZ cone (UA/EC); and (8) UA/TPGDA + ZnO/ TPU (UA/PU ). Eighty 1-mm-thick root slices prepared from extracted human permanent molars were randomly divided into 8 groups with 10 specimens in each group . Root slices were filled with the above obturation materials, and then push- out test was performed with a universal testing machine. The results showed that the UA/EC and UA/PU groups had significantly higher bond strengths than the other groups