The procedure (in Class III restoration) shown is:
Larger preparations may require additional beveling of the accessible enamel walls to enhance retention by bonding these enamel margins, which are beveled with a flame-shaped or round diamond instrument.
The bevel is prepared by creating a 45-degree angle to the external surface and to a width of 0.5 to 2 mm, depending on the size of the preparation, location of the margin, and esthetic requirements of the restoration.