Shade Selection
Recommended Shade Guides: Ivoclar Chromascop®, Vita Lumin.
General Considerations:
All single-unit crowns, inlays, onlays and crowns
should have adequate tooth structure to allow for the marginal placement
to be at or above the free gingival margin tissues.
IPS Empress 2 full coverage crowns and bridges should be prepared so that
all margins are at or above the free gingival tissue. If the preparation
requires cervical extension, the margin placement should be on sound tooth
structure not invading the biological width.
Empress 2 framework material should be at least 0.8 mm in thickness for
optimal strength.
It is necessary to take a stump shade with Empress 2.
Incorporate taper of 8 to 10 degrees (never more than 12º)
Tooth preparation length should reflect a 1.5 to 2.0 mm occlusal (incisal) reduction.
All teeth considered for use as bridge retainers
must provide adequate clinical crown length to allow for preparation to
achieve ideal resistance and retention form.
The clinical crown length of the retainer tooth next to the edentulous
space must be of adequate length to allow for the required occlusal-gingival
connector height. These critical connector dimensions are directly related
to the occlusal force they are required to function against.
In the anterior region, the connector dimensions are to be 4 mm (occlusal-gingival)
and 4 mm (buccal-lingual).
In the premolar region, connector dimensions are to be 5 mm (occlusal-gingival)
and 4 mm (buccal-lingual).
Pontic Span
Maximum pontic spans will vary from patient to patient depending on the
tooth position, size, condition and arch position of the retainers.
Pontic spans should not exceed 9 mm posterior to canine and 11 mm anterior
to canine.
Measurements for this determinant are made from the unprepared abutment
surfaces next to the edentulous space.
