Development of a new direct core build-up method using a hollow fiber-reinforced post.

We have developed a new direct construction method for core build-up starting with the hypothesis that an improvement in pullout strength and a decrease in the number of voids in the restorative material will become possible by filling a hollow fiber reinforced post with the restorative material from the bottom of the root canal. For the pullout test, the hollow post was fixed to the head of a mixing tip and inserted into the bottom of a cylinder. The restorative material was then injected through the hollow post. The pullout load of the hollow posts was significantly higher than that of the solid fiber posts. The number of voids observed in the restorative material when using the hollow post was about 1/5 of that in the case of the solid post.