Figure 1.

SEM image of dentin-resin interface when Prime & Bond NT (PB NT) was applied after H3PO4 application. a) For superficial dentin, a thin and uniform hybrid layer can be observed. Funnel-shaped and long resin tags with some lateral branches are evident (bar=2 µm). b) For deep dentin, wide and long resin tags were exhibited. These resin tags were also funnel-shaped, so the removal of the peritubular dentin by the acid treatment was evident. Numerous small lateral extensions of micro-tags branching off at right angles from the main resin tag were frequently observed (bar=10 µm).