Page 60 - CEREC Q2 | 2014

58 | CERECDOCTORS.COM | QUARTER 2 | 2014
Fig. 12: Vita Real-Life
block
Fig. 13: Sirona CEREC
Blocs C In
Fig. 14: Positioning
restoration in the block
CASE 3
Here we have existing PFM restora-
tions (Fig. 9). Since the teeth are already
prepared for full-coverage traditional
crowns, the assumption can be made
that there is a lot of tooth preparation
underneath — preparation that has
likely removed all of the enamel and a
good portion of dentin.
The restorative material of choice
has to replace not only the enamel,
but also a good portion of the dentin.
In this case, there is a bit of a chal-
lenge. Ideally we would like a high-
value opacious core with less than
1 mm of enamel. This is quite easy
for a laboratory, but how can we
create this with monolithic materials
with no cutback?
There are a couple options that can
be considered. The e.max CAD ceramic
will be great for strength. However, the
more opacious (LT) it is, the less esthetic.
Depending on the discoloration, we
can choose a more translucent e.max
material (HT or Impulse), but we must
compensate for the value drop. Some
techniques to do this might be choosing
a color that is two shades lighter than the
desired shade or increasing the spacer
and using a more opacious, higher-value
resin cement.
There are two other novel materials
that are theoretically perfect for this
scenario: Vita Real-Life (Fig. 12) and
Sirona CEREC Blocs C In (Fig. 13). Both
of these blocks behave in similar ways.
There is an opacious dentin core at
the center of the block with an enamel
coating around it. This allows you to
position the restoration within the block
in a way that will mimic the natural
tooth. The difference between the two
blocks is how they are positioned. The
Vita Real-Life is manually positioned
within the block (Fig. 14) and the Sirona
CEREC Blocs C In is automatically
positioned within the block based on
Restoration Color and Incisal Edge
| | | S K R A M S TA D
12
13
14
15
16
17
parameters entered in the software
(Figs. 15-17).
When choosing a restorative material
for a case, there cannot be a universal
choice all the time. We must allow
ourselves to visualize what we are trying
to do and, more importantly, consider
how much we have to prepare the tooth
to achieve that goal. Understanding this,
along with the optical properties of the
natural tooth, will allow you to choose
the ideal material for the most esthetic
and functional result needed.
For questions and more information,
Dr. Skramstad can be reached at
mike@cerecdoctors.com.
Figs. 15-17: Sirona CEREC Blocs C
In positioning