Figure 2. Representative images of adhesive interface between dentin and adhesive system. (A, B) G1; (C, D) G2; (E, F) G3; (G, H) G4. (A) image in 2D; (B) image in 3D. Arrows indicate hybrid layer thickness.

G1, ethanol and immediate acid etching; G2, xylol and immediate acid etching; G3, ethanol and etching 7 days later; G4, xylol and etching 7 days later.