Page 26 - CEREC Q4 | 2014

24 | CERECDOCTORS.COM | QUARTER 4 | 2014
the right techniques and right
combination of materials can make
all the difference in the efficiency of a
case, as well as for its long-term pros-
pects. This is particularly evident for
CEREC users, who often choose their
own combinations of products based on
recommendations from colleagues, anec-
dotal reports, marketed literature and/or
in-office experimentation. However,
with the right combination of restor-
ativematerial and adhesive resin cement,
practitioners can be assured that they are
giving patients the best results.
Selecting the appropriate cement
for CEREC procedures is a matter of
balancing what is required by the restor-
ative material with what the dentist
prefers in terms of ease-of-use, handling,
mechanical properties and other factors.
Highbond and compressive strengths are
of course vital, but the dentist will also
likely consider matters such as esthetics,
number of application steps and adhesive
compatibility.With these factors inmind,
many chairside CAD/CAM users have
recently come to favor 3M ESPE RelyX
Ultimate Adhesive Resin Cement. This
cement is often demonstrated in cases
with3MESPELavaUltimateRestorative,
as will be shown here, but it is also indi-
cated for usewith any other glass ceramic
block material, including the popular
e.max CAD and even the polycrystal-
line ceramics (zirconia). This makes it a
very useful tool for CEREC
dentists by eliminating the
need for any other adhesive
resin cement.
Choosing the Right Cement
for CAD/CAM Restorations
The Right Combination of Restorative Material and
Adhesive Resin Cement Assure Best Results
C A S E S T U D Y | | | B Y D A N I E L J . P O T I C N Y, D . D . S .
Do not underemphasize the need
to obtain the highest possible bond
strengths to tooth substrate. While
self-adhesive resin cements are often
adequate for a given case, they still
will not perform to the highest level
when sufficient amounts of enamel are
present and for which phosphoric acid
is used to create deep penetration of
the resin tags for the adhesive compo-
nent.1,2 Furthermore, the use of a “well-
designed adhesive/cement combina-
tion” can help streamline and create
predictability withwhat, in the past, was
often a complicated procedure requiring
three or more bottles. The cement used
here is optimized for use with 3M
ESPE Scotchbond Universal Adhesive,
which allows the dentist to use just two
components for adhesive cementation.
The following case will demonstrate the
use of the material for a typical crown
replacement.
3 1
2
Fig. 1: Preoperative view of the fractured
PFM on #2
Fig. 2: A depth cut was made through
the PFM
Fig. 3: The preparation prior to imaging;
a dual-cord technique was utilized
CASE PRESENTATION
The patient, a 48-year-old female,
presented with a fractured PFM on #2
(Fig. 1). To remove the crown and effi-
ciently prepare the tooth for a replace-
ment, depth cuts of 2 mm were made
through the existing PFM to remove it
and simultaneously establish the proper
reduction needed for the chosen block
material. Two mm over cusps an 1.5 mm
in fissures are theminimal specifications
for all of the currently available glass and
polymer/glass containing block mate-
rials (Fig. 2). This is much more predict-
able than first removing the crown and
attempting to do the same when spatial
orientation to the desired outcome
cannot be easily visualized.
The preparation was refined after
removal of the PFM, and a dual cord tech-
nique was used to prepare the margins for
scanning (Fig. 3). As we know, the CEREC
camera cannot see through blood or saliva,