Fig. 4. SEM micrograph of fractured surface after SBST (original magnification ×400). Closer examination shows similar pattern to SEM views for original magnification ×100. (a; detached surface of resin cement, adhesive, b; resin cement, c; exposed dentin) (A) Group 0d, typical SEM micrograph of fractured surface after SBST from control group. (B) Group 1d, small portion of detached resin cement and unharmed interface of overlaying resin cement is on dentin surface. (C) Group 2d, most of exposed dentin is covered with resin cement (b), while detached surface of resin cement (a) is found in a small portion. (D) Group 7d, larger detached surface of resin cement (a) reveals adhesive. (E) Group 14d, most of resin cement has detached from dentin surface coated by adhesive (a). Exposed dentin (c), which suggests failure in dentin, is clearly detectable in groups 7d and 14d.
