Figure 2.

The four-point flexure configuration for evaluating the bonded interface. Denoted are the resin composite (C), dentin (D) and the twin bonded interfaces comprised of resin adhesive and hybrid layer (A+H).

a) Geometry of the loading configuration and location of the interfaces. b) A class two restoration subjected to forces of mastication on vertical and horizontal plane. The squares represent the relevant sites of the dentin sections that are consistent with the current test method and the encircled portion represents the interfaces with configuration consistent with the bonded interface specimen.