Optimal enamel bevel features for a class 3 or 4 composite is:
Enamel margins are beveled with a FLAME SHAPED OR ROUND DIAMOND INSTRUMENT.
Bevel is prepared by creating a 45 degree angle to the internal surface and width of 0.5-2 mm depending on the size of the preparation, location of margin and esthetic requirement.
45 degree bevel with 0.5-1.5 mm width
30 degree bevel with 0.5-1.5 mm width
45 degree bevel with 2-3 mm width
30 degree bevel with 2-3 mm width