PDF Version - Glidewell Dental Labs

Figure 44: Because I’m not using a double-arch
tray, I have to take a bite registration so that the
lab will be able to articulate the models. With
full upper and lower models, it would be pretty
easy for the lab to hand articulate the models
and verify with wear facets, but the use of a
bite registration does a good job of verifying
the mounting. A properly done bite registration
should only contact the incisal third of the teeth
that have been prepped, and the incisal third of
the opposing teeth. It will be trimmed back in
the lab, but try to keep the registration material
off the soft tissue.
Figure 45: When removing a polyvinyl siloxane
impression from the mouth, do it gently with
a slight rocking motion. This cord technique
gives us a deep subgingival impression of the
root structure, so we want to make sure we give
the material the chance to stretch and pull the
bottom cord off the sulcus if it is attached. This
is the opposite of an alginate impression, which
should be removed with a sudden snapping
motion. One of the benefits of silicon impression
materials is their ability to set in an undercut and
be removed without tearing, so give it a chance
to release.
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Figure 46: It has been five days, the temps have
been removed, and the preps cleaned with
Consepsis ® (Ultradent). The more I shorten the
time between prepping and seating, the less
adjustments and the lower remakes I have. The
best example of this is same-day restorations
and their almost nonexistent remake rate. My
hope is that as digital impressions continue to
make inroads into more dental offices, threeday
turnarounds will become the standard for
model-less monolithic crowns. The temporary
crown is the biggest source of error and movement
in the crown fabrication timeline, and the
less time that it is in the mouth, the better the
chance the crown will drop into place without
any adjustments.
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