Failure criteria of dentin–resin adhesion – The J-integral approach

In dentistry, current tests to determine the bond strength of dentin–resin adhesives are simple but result in large variations in the cleavage load. Our numerical results show that these variations could be minimized by using linear elastic fracture mechanics to analyze tensile specimens into which a subcritical precrack in the adhesive layer which initiates crack propagation has been introduced. In our model, the minimum fracture toughness was obtained when 11% of mode II fracture accounted for the differences in the elastic moduli of the dentin and the resin.