Figure 4. SEM micrographs showing the fractured surface of Prime & Bond NT. (A) Total fractured surface at the dentin side of a specimen made with wet bonding. Higher magnification of the sections of the fractured surface areas marked (B) and (C) in (A). (C) The widening of the dentinal tubules at the demineralized dentin was caused by the effect of acidification without impregnation of the bonding resin at this portion. B, bonding resin; TH, top of the hybrid layer; WH, within the hybrid layer; DD, demineralized dentin.