Abstract
This study investigated the best conditions for adhesion between dental casting alloys and thermosetting resins.Four commercial alloys(Au alloy, Ag-Pd-Au alloy, and two Ni-Cr alloys)and a visible light-cured and heat-cured thermosetting resins were used.The interface between alloy and resin was analyzed by EPMA.The adhesive strength between alloy and resin was measured after sand blasting or acid etching treatment, and the strength of adhesion after thermal cycling was also examined.Tight adhesion between alloy and resin was observed after both sand blasting and acid etching treatments.The adhesive mechanism was principally mechanical, since no interdiffusion layer of elements composed of alloy and resin was observed by EPMA.The surface treated with sand blasting was effective for the mechanical bond between alloy and resin.The adhesive strength increased with decreasing thickness of the opaque resin layer.The adhesive strength remarkably decreased by increasing the number of thermal cyclings.
