Influence of a dentin bonding agent on the fracture load of Dicor.

The purpose of this investigation was to evaluate the effect of a dentin bonding agent on the fracture resistance of a cast glass-ceramic luted to dentin. Sixty beam-shaped Dicor specimens and 40 bovine dentin specimens of similar dimension were prepared and randomly distributed among three groups of 20 each: Dicor specimens (control); Dicor specimens luted to dentin with Dicor Light-Activated Cement; and Dicor specimens luted to dentin with Prisma Universal Bond 3 dentin bonding agent and Dicor Light-Activated Cement. All samples were thermocycled and loaded to flexural failure with an Instron Universal testing machine. The mean fracture loads of the three groups were all statistically different from one another (P < .05). The use of a dentin bonding agent increased the fracture resistance of the resin-cemented glass-ceramic samples by more than three-fold compared to those luted with resin cement alone. The results of this study suggest that the use of a dentin bonding agent in combination with dual-cure resin cement will increase the fracture resistance of castable glass-ceramic restorations.