Page 57 - CEREC Q1 | 2014

QUARTER 1 | 2014 | CERECDOCTORS.COM | 55
implant would be placed on the center
of the ridge. It was therefore decided
to place the implant as far buccally as
possible without risking nerve damage.
Final implant placement was deter-
mined based on the CEREC Omnicam
and GALILEOS scans, and the implant
was placed and allowed to heal. The
implant was deeply set due to the height
of the crest being lost.
Oncefullyintegrated,ascrew-retained
restoration was selected to provide
the best restorative result (Fig. 2). The
high level of adjacent tissue would have
increased the difficultly of completing
the case with a cement-retained
restoration. The interproximal margins
were extremely subgingival and, there-
fore, would have made residual cement
clean-up difficult. This concern was
eliminated by selecting a full-contour,
screw-retained lithium disilicate crown
(IPS e.max, Ivoclar Vivadent).
The healing cap was removed, and
the new scan post was placed (Fig. 3).
The extra height of the scan post in this
case enabled easy verification of proper
engaging marker alignment.
When entering the case in the 4.2.3
CEREC software, care was taken to
designate the biogeneric individual
abutment (Fig. 4). A screw-retained
restoration was selected and, therefore,
multi-layer was not required. The scan
post option was also selected. Then, the
abutment restoration selected was IPS
e.max CAD, after which the scan post
was imaged and the models created.
After stitching the buccal bite and
setting the model axis, it was deter-
mined that trimming the area was
necessary; unlike with traditional crown
and bridge restorations, this step should
not be overlooked. Once the model was
trimmed, the scan body head was desig-
nated. The base lines were then edited,
taking care to keep them close to the
edges of the abutment (Fig. 5). Note that
the farther away from the healing abut-
ment that the line is drawn, the more
gingival pressure is applied.
The restoration axis was defined
according to the proposed restoration
angle. The restoration was placed so
that the axis matched the long axis of the
implant veryclosely, if not perfectly (Fig. 6).
If the implant is placed at a slight angle,
the restoration axis would have to match
the adjacent teeth to prevent having a
proposal that would require significant
4 5
7 6
Fig. 6: The restoration was designed so
that the axis matched the long axis of
the implant very closely
Fig. 7: The contours were designed using
form and shape tools
Fig. 4: The case
was entered into
the CEREC soft-
ware to design
the abutment
Fig. 5: As it was
created, it was
important to
keep the base
line close to the
edges of the
abutment