Page 6 - CEREC Q1 | 2014

one of the greatest challenges in
CEREC dentistry is creating a correct
occlusal relationshipof the virtualmodels.
Onlywith an accurate relationship canwe
have the opportunity to create restora-
tions that require minimal post-insertion
occlusal adjustment or models that inte-
grate accurately for guided surgery.
To achieve a correct relationship, we
need to accurately image themodels and
correctly take a buccal bite.
Here,we reviewaprotocolforOmnicam
imaging and buccal bite. When imaging
with the Omnicam, one must understand
how the software builds the models and
the challenges that are presented.
Thinkof it thisway: there is acurve inan
arch, and we know that when if we were
to attempt to lay a flat, rectangular picture
on a sphere, there would be distortion
(Fig. 1). This is the challenge that we face
in Omnicam and Bluecam
imaging. We must minimize
the distortion in the creation
of themodels.
Protocol for Omnicam
Imaging and Buccal Bite
Ensuring the Correct Relationship of the Virtual Models
S O F T WA R E | | | B Y B O B B Y C H A G G E R , D . D . S .
to the scaffold. In the posterior area, one
must always start the imaging on the
occlusal surface. From the occlusal, one
must rotate the camera to the buccal,
and then rotate back on the same semi-
circle to the lingual (Fig. 3). The camera
then returns to the occlusal surface for
mesial or distal movement along the
rail (Fig. 4). In this fashion, the virtual
model is built upon the scaffold, and we
are able to create an accurate model.
SINGLE-RAIL IMAGING
IN THE ANTERIOR
When imaging the anterior sextant with
the Omnicam, it is apparent that starting
imaging on the incisal edge is difficult.
This is due to the inability to capture
the “stitch” on the lingual or the buccal
because of the depth of the floor of the
mouthor thevestibule. Inthis instance,we
mustmove the rail to the facial. Analogous
towhere the archwire is in orthodontics.
The Omnicam camera must only move
mesiallyordistallyalongthisrail.However,
When imaging the mouth, one must
use a scaffold upon which to grow the
virtual model — much in the same way
that a scaffold is used to build a building.
The scaffold is used as a rail upon which
to grow themodel (Fig. 2).
SINGLE-RAIL IMAGING
IN THE POSTERIOR
In the mouth, consider the Omnicam to
only have the ability to move mesially or
distally upon a rail. This rail is analogous
3
1
2
4
5 6
Fig. 3: Posterior sin-
gle-rail imaging:
occlusal, buccal
and lingual
Fig. 4: Single rail:
quadrants or
sextants
Fig. 5: Anterior sin-
gle-rail imaging:
facial, incisal
and lingual
Fig. 6: Anterior
sextant single rail
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Fig. 1: Rectangle
picture on sphere
Fig. 2: Scaffold to build model