Figure 1. Transmission electron micrographs showing the nanoleakage in phosphoric-acid-etched enamel (control) that was bonded with Prime&Bond NT. (A) A low-magnification view of the resin-enamel interface. C, resin composite; A, adhesive containing nanofiller particles; E, prismatic enamel; arrow, interprismatic sheath. (B) A high-magnification view showing the presence of isolated, electron-dense silver grains (open arrowheads) within the etched, resin-infiltrated enamel (E). Apatite crystallites were partially dissolved and exhibit central hole regions (pointer). Arrow: nanofiller clusters within the adhesive layer (A). (C) A very high magnification of (B), showing the presence of the central dark line (pointers) within a partially dissolved apatite crystallite.