Fig. 3.

TEM of XP Bond-bonded, air-dried, collapsed acid-etched dentin that re-expanded after immersion in the second experimental PAA- and PVPA-containing remineralization medium. Specimens were examined after 2 months (A–C) and 4 month (D–F) of biomimetic remineralization. Abbreviations: C: composite; A: adhesive; H: hybrid layer; T: dentinal tubule; D: mineralized intertubular dentin. A. A low magnification view of a two-month old specimen showing extensive mineral deposition in the middle part of the hybrid layer (between pointers). The surface 1 μm (open arrow) and the base of the hybrid layer were better infiltrated by resin and did not remineralize. B. A moderately high magnification view of Fig. 3A showing the heavily mineral-filled, remineralized superficial part of hybrid layer (asterisk) beneath the well resin-infiltrated, non-remineralized basal part of the hybrid layer (open arrow). Open arrowhead: adhesive nanofillers. C. A high magnification view of the remineralized hybrid layer showing that the minerals exists as needles (open arrowhead; ca. 50–70 nm long) and plates (pointer; 25–35 nm long). D. A low magnification view of the resin-dentin interface after 4 months of biomimetic remineralization. The full thickness of the hybrid layer was depicted by two open arrows. Heavy remineralization could be identified from some parts of the hybrid layer (asterisk). E. A moderately high magnification view of Fig. 3D showing that the mineral density of the remineralized hybrid layer (asterisk) was similar to that of the underlying dentin. The top (open arrow) and the base (pointers) of the hybrid layer were better infiltrated and did not remineralize. F. A high magnification view of the heavily remineralized hybrid layer in Fig. 3D showing the presence of a dense arrangement of mineral platelets (pointers) and needles (open arrowhead).