Different types of burs are used to prepare different type of margins of a crown preparations. They are as follows:
Chamfer Finish Line:
The round and tapered cylinder and torpedo diamonds are used to prepare a chamfer finish line.
Shoulder Finish line:
The end cutting burs are used to prepare the shoulder finish line.
The radial fissure bar or flat end tapered diamond burs are used for radial shoulder finish line.
Tapered fissure burs are used to prepare the groove.
All ceramic Crowns Finish Line:
Shoulder finish line is the choice of finish line for all ceramic crowns. The wide ledge provides resistance to occlusal forces and minimizes stresses that might lead to fracture of the porcelain.
Shoulder with a bevel:
It can be used for the facial finish line of metal ceramic restorations where aesthetics are not critical, for example, in posterior teeth.