Abstract
This study investigated the temporal changes of dentin bond strength in dual-cured resin core foundationsystems. Three core foundation systems, Estecore (EC, Tokuyama Dental), Clearfil DC Core Automix ONE (DC,Kuraray Noritake Dental) and Unifil Core EM (UC, GC), were used.The adhesive resin was applied on the surface of bovine dentin and light activated for 10 seconds. Then, coreresin paste was filled onto the surface and cured (specimens with irradiation). For the specimens withoutirradiation, neither the adhesive nor the core resin was light activated. After 10 minutes, the specimens wereimmersed in water for 10, 30 or 60 minutes and 6, 12 or 24 hours, then shear bond strengths were measured.The bond strength increased over time for each system. The behavior of the changes in bond strength differedboth by the system used and the irradiation conditions. In EC, the bond strength increased over time faster thanthe other two systems, and was not affected by the irradiation. DC and UC with irradiation showed higher bondstrength than those without irradiation.The results showed that the development of dentin bond strength of resin core foundation systems is influencedby the systems used and the curing condition.