Inlay Bridges
Using Cercon
by Veeraraghavan V. Sundar, Ph.D., Nels O. Ewoldsen, D.D.S., and Robert M.
Michael, C.D.T.
The Cercon system from Dentsply Prosthetics allows dental professionals to
bring their wealth of clinical and lab experience together to create a
restoration that is best suited for a patient's needs. Professionals can
use Cercon zirconia frameworks for all single units, two-abutment bridges
with a maximum mesial-distal span of 38 mm, and longer bridges with
multiple abutments up to a 47mm linear span. As a new esthetic option,
clinicians can now present patients with metal-free Cercon inlay bridges
that match porcelain fused to metal inlay bridges in load bearing
capacity.
Clinical recommendations
Inlay bridges are a conservative restorative option, especially when
the professional or patient is concerned about preserving natural tooth
structure. Preparing a restorative site for a Cercon inlay bridge is
relatively straightforward and comparable to preparing for other inlay
restorations. Inlay bridges are typically single-span (three-unit)
constructions used for replacing a missing second premolar. Inlay bridges
to replace first molars should be considered only in very carefully
selected cases if the occlusal relationships are favorable and if the
width of the pontic is 10 mm or less.
Keep the following guidelines in mind when
preparing an inlay-retained bridge:
Full coverage abutment:
-
Prepare a full-coverage
abutment conventionally, with ≥ 1 mm axial and ≥ 1.5 mm occlusal reduction
and smooth line angles.
-
The full coverage
abutment may be conventionally cemented or adhesively bonded.
Inlay abutment:
-
Take care to ensure
sufficient proximal box width (4 mm) and appropriate height (4-5 mm).
-
The connector area
should be not less than 9 sq. mm.
-
The recommended
preparation angle of divergence is 2 to 3 degrees.
-
The preparation should
have smooth rounded line angles and be free of retentive elements.
-
The angle between the
facial and lingual aspects of the proximal box and the tooth's external
surface should be between 70 and 90 degrees.
-
Vestibular or lingual
extensions, and beveling of cavosurface margins are not recommended.
-
For maximal retention
of the inlay abutment, we recommend bonding adhesively.
(This article was originally published in
Aesthetic Dentistry, Winter 2005 issue.)
Veeraraghavan Sundar, Ph.D., M.B.A., is a
graduate of the Intercollege Program in Materials, Pennsylvania State
University. He manages new product commercialization for DENTSPLY
Prosthetics.
Nels Ewoldsen, D.D.S., M.S.D. is a
graduate of Indiana University School of Dentistry. He directs clinical
research for DENTSPLY Prosthetics.
Robert Michael, B.S., C.D.T., is a
graduate of Tusculum College and East Tennessee University, and a
technical specialist at DENTSPLY. |
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