Figure 2.

The OCT scanning images of each step. (A) Step 1: the surface of the incisor was clean; (B) Step 2: 37% phosphate etching agent was evenly applied to the incisor for 15 min, after which the surface was clean and dried; (C) Step 3: Icon-Etch was smeared evenly on the surface of incisor for 30 s, after which the surface was clean and dried; (D) Step 4: Icon-Dry was smeared evenly on the surface of incisor and kept for 1 min, after which the surface was dried; (E) Step 5: Icon-Infiltrant was smeared evenly on the surface of maxillary incisor for 1 min and light-cured for 40 s. Red arrow: the surface of the enamel. White arrow: enamel-dentinal junction (EDJ). Green arrow: resin layer. Scale bar is 400 μm.