Page 24 - CEREC Q3|2013

22 | cerecdoctors.com | quarter 3 | 2013
sirona’s mcxlmilling unit has been
the benchmark for in-office milling since
its release in2008.Havingmilledmillions
of restorations worldwide, it has been
a workhorse for the restorative dentist
looking to create well-fitting restorations
in a single visit. With the recent release
of the new MC milling unit, Sirona is
now able to offer a more cost-effective,
entry-level option for dentists who are
either beginning their CEREC journey or
looking to upgrade from the old compact
milling units.
This is a straight-forward case study
showcasing the milling efficiency and
accuracy of the MC when used in
conjunction with the latest version 4.2
chairside software. The patient has a
very common problem; one that the
restorative dentist encounters on a daily
basis. The old, existing DO amalgam
restorationwas failing and, subsequently,
the patient fractured the DL cusp (Fig. 1).
The decision was made to restore the
toothusing theOmnicamandMCmilling
unit to create an onlay.
The existing amalgam and secondary
decay were excavated. The cavity was
prepped appropriately, ensuring adequate
taperofallwalls,andasmoothfloorandbox
form. Biogeneric Individual was selected
as the design mode and the prepared arch,
opposing arch and buccal
bite were efficiently imaged
using the Omnicam (Fig. 2).
Software version 4.2 offers
A Perfect
Match
Sirona’s New
MCMilling Unit
and the New
Vita Enamic
c a s e s t u d y | | | b y B o b C o n t e , D . M . D .
solid addition to the existing line of
milling choices available to the CEREC
dentist.With theexceptionof a fewlimita-
tions as to the materials available to mill,
there is no noticeable drop-off in preci-
sion and efficiency when compared to the
MCXL. Factors such as noise, bur wear
and footprint are identical to the MCXL.
On average, mill times are slightly longer,
but not significant enough to be a concern
in a busy restorative practice.
For questions or more information,
Dr. Conte can be reached at
dr.conte@yahoo.com.
several features not available in previous
versions. These features allowthe software
to propose a restoration that requires very
little manipulation. Advancements such as
the ability to set the proper model axis as
well as virtual articulation create restora-
tions with excellent anatomical form
and accurate occlusal and interproximal
contacts (Figs. 3-4).
Once designed, the restoration is sent
to the Mill Preview (Fig. 5). The material
of choice is the new VITA Enamic block.
Enamic is different from any other dental
material to date. It is an interconnected
network of ceramic and polymer. It
combines the best properties of both
composite and ceramic into one material.
Ceramics have excellent esthetics, color
stability, stiffness and resistance to wear.
Compositeshave the ability tomill veryfine,
delicatemargins.Theyarealsoveryresilient
and kind to the opposing dentition. This
material mills very quickly and very accu-
ratelywith theMCmilling unit (Fig. 6).
The Enamic block is also very easy on
the diamond burs of the milling unit; the
reported life expectancy is more than 100
mills with a single set. In this particular
case, total mill time was less than seven
minutes (Fig. 7). The resulting restoration
exhibits excellent milling of all margins,
even in very thin areas. The onlay drops
right into place with no adjustments and,
once cemented, blends in beautifully with
the existing dentition (Fig. 8).
The MC milling unit provides a very
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