Effect of dynamic loading on the integrity of the interface between root canal and obturation materials

The purpose of this study was to evaluate the effect of occlusal load on the integrity of root canal obturation. Maxillary anterior teeth were cleaned, shaped, and obturated with either gutta-percha (GP)/AH Plus or Resilon/Epiphany. Afterwards, teeth were placed under 100 N force at 2 Hz for 22 hours in a 37 degrees C water bath. Teeth were sectioned and examined for disruption in the integrity of the obturation by using optical microscopy. The length of the separation between the obturation and the root canal walls was measured and compared statistically. GP and Resilon obturated canals subjected to occlusal load displayed significantly greater interface disruption compared with unloaded controls (p <.05). The results indicate that occlusal load generates separation forces on the obturation interface that might compromise the sealing ability of the obturation.