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Figure 7: Crowns often look fake in the gingival third, but this
gingival depth cut ensures that we will deliver an esthetic crown.
Because the depth cut is a perfect half circle, we will be left with a
perfect quarter circle — which is a precision deep chamfer or shallow
shoulder — after we do our axial reduction. There is no easier
way to prep a perfect margin.
Figure 8: I prepare a 2 mm depth cut in the incisal edge because
we are restoring the tooth to its original length. I typically place two
of these cuts, which help me quickly reduce the incisal edge while
keeping it level. Under-reduction of incisal edges leads to crowns
that are facially prominent in the incisal third, which gives them a
bulky look.
Figure 9: With the depth cut bur perpendicular to the facial surface
of the tooth, at the junction of the incisal third and the middle, we
make a 1.5 mm depth cut. This depth cut should be just apical to
the incisal edge depth cuts. Depth cuts ensure that we get enough
facial reduction to have an esthetically pleasing crown that is the
same size as the adjacent natural tooth. This is difficult to achieve.
Figure 10: At this point, all depth cuts are finished. This allows me
to fly through the rest of the prep because the gingival is essentially
done. The incisal edge takes about 15 seconds, and the facial
reduction is marked with a depth cut. There is no guessing about
how much to reduce.
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