FINISH LINE CONFIGURATION
Chamfer
It’s a finish line
design for tooth preparation in which gingival aspect meets the external axial
surface at an obtuse angle. This type is prepared with a tapered round ended
fissure diamond bur.
Advantages
•
It provides
distinct margin
•
Adequate bulk
to the restoration
•
Easier to
control
•
Exhibits least
stresse
Disadvantage
•
Care needed to
avoid unsupported lip of enamel Indications:
•
Cast metal
restorations
•
Lingual margin
of the metal ceramic crowns
Shoulder
The shoulder finish line
is a design for tooth preparation in which the gingival floor meets the
external axial surfaces at approximately a right angle. This finishing line is
prepared with flattened end tapered diamond fissure bur.
Advantages
•
Bulk of the
restoration
•
Wide ledge
provides resistance to occlusal forces
•
Provides space
for healthy restorative contours
•
Maximum esthetics
•
It offers
resistance against distortion during processing
Disadvantages
•
Less conservative
of tooth structure
•
The sharp 90
internal line angle
Indications:
•
All ceramic
restorations
•
Facial margins of
metal--ceramic crowns
