Push-out test of a novel root canal filling material

Objectives:

Adhesion of the root canal filling material to dentin is important to prevent the dislodgement of the materials. We have developed a visible-light curable urethane-acrylate/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 cone material. The purpose of this study was to compare the push-out bond strengths of the TPU-based filling system we developed with the other filling materials.

Methods:

We filled the prepared canal of the 1mm root slices with different filling materials. Then the root slices were put in the special punch-out apparatus and we used the Instron universal testing machine to evaluate the push-out bond strengths.

Results:

The mean bond strengths(MPa) were as follows: TPU-based filling material: 10.92+-3.88, Gutta percha/ Tubliseal: 3.81+-0.87, Resilon system: 2.93+-0.87. The TPU-based filling material exhibited significantly higher bond strengths than the remaining groups.

Conclusions:

The results indicates that the TPU-based filling system exhibits better adhesion to dentin and has excellent potential to be used as a root canal filling material.