Abstract
In order to decrease the polymerization shrinkage stress of resin, increase core stiffness, and reduce the treatment time needed for direct resin core construction, we proposed a new method in which megafiller is inserted into the resin core. In this study, the reinforcement effect of the megafiller was examined. Alumina and stainless steel balls of 3 or 4 mm in diameter were used as a megafiller, and were treated with silane coupling agent or metal primer, respectively. Two 3mm balls or one 4mm ball were inserted into composite resin cores of 5mm in diameter and 8mm in height. The mechanical properties of these cured resin cores were determined by a compression test. Although the compressive strength of the resin core was not changed with the insertion of megafiller, the elastic modulus and yield stress increased via its insertion, regardless of ball composition or number.
