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milling units and a brand new furnace called the “CEREC Speed-
Fire.” In this article, I will review the workflow in detail with a
clinical case. But first, let me describe the two features that are
important, the milling and the new furnace:
•
milling:
TheMCX andMCXL Practice Labmilling units now
have the option for dry milling capabilities. What this means is
that it can mill all the traditional materials that CEREC offers in
a “wet environment” (the same as it has always done). It also has
the ability tomill zirconia in a “dry environment” with the aid of
a newevacuation unit that is attached to themilling unit.Milling
zirconia dry has advantages when it comes to sintering time
(it doesn’t have to be dried, which lowers the firing cycle). This
will be described below. It should be noted that all the current
wet milling units can mill (carbides) or grind (diamonds)
zirconia in a wet environment. Current users will NOT have
to buy a new milling unit to participate in the new workflow.
Milling or Grinding in a wet environment will only add 10 to 12
minutes to the sintering time (additional drying cycle).
•
cerec speedfire:
The “magic” of the entire process is the new
furnace. A revolutionary accomplishment that allows you to not
only speed-sinter zirconia, but also run a stain/glaze cycle. You
read that right… a single furnace for both sintering and glazing
restorations! If you mill zirconia dry, the sintering time is only
about 15 minutes; if you mill/grind wet, the process is about
27 minutes. After you sinter the restoration, the glazing process
(including cooling) is only about 7:30. Another great feature of
the CEREC SpeedFire is its incredibly small footprint. It can be
set on any table or countertop like any other oven. To top it all
off, it communicates wirelessly with the CEREC software as a
device. Based on what you are doing, the CEREC software auto-
matically transfers the proper cycle to the oven after the resto-
ration is milled!
fig. 4:
The preparation was marginated in the 4.4.1 software.
Note that a deep chamfer margin design was used, the lack of
enamel, and how subgingival the margins are, reinforcing the
decision for a cementable restoration.
fig. 5:
Initial Biogeneric proposal. Note the excellent anatomy and
the fissure thickness of .91mm. Two advantages of using zirconia is
that it can bemilled a little thinner and, because it uses fine finishing
carbides andmilled roughly 20 percent larger, themilled anatomy
will bemore defined that traditional CEREC ceramics.
fig. 6:
When you go to theMill Preview, you will be prompted to
choose the final shade of the zirconia restoration. This shade
information will have a direct effect on the firing times in the
CEREC SpeedFire furnace.
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