Page 7 - CEREC Q1 | 2014

QUARTER 1 | 2014 | CERECDOCTORS.COM | 5
imaging must involve rotation of the
camera by 90 degrees (Fig. 5). The camera
must be rotated over the incisal edges of
the teeth to the lingual. On the lingual
side, one must rotate the camera slightly
toward the direction that one will eventu-
ally bemoving the camera on the rail. This
action is done so as to facilitate an easy
“stitch”when rotating the camera over the
incisal edge afterwe havemoved along the
rail. The camera is then rotated back to its
starting position on the rail. Then, move-
ment along the rail can be accomplished in
amesial or distal direction (Fig. 6).
DOUBLE-RAIL IMAGING
IN THE ANTERIOR
A secondmethod for imaging in the ante-
rior sextant is one that employs a double
rail. One would employ this method if
they are having difficulties employing the
single-rail system. Imagine a rail running
along the facial of the anterior sextant
and a rail running along the lingual of the
anterior sextant. The camera will only
move mesially or distally along this rail.
When imaging is started, the camera
will be rotated 90degrees as in the single-
rail system, and will only be moved incis-
ally to the incisal edge and gingivally to
the point that you want to image. The
camera will then be brought back to the
rail for movement along the rail.
There is no need to rotate the camera
to the lingual of the teeth. Once one has
moved along the rail, the action of moving
the camera incisal and gingival is repeated.
At the canine area, the camera is rotated
to the lingual, and imaging of the linguals
is completed. In the lingual, the camera
is moved incisally and gingivally and then
brought back to the rail. Movement is then
accomplished along the rail so as to repeat
the incisal and gingival imaging (Fig. 7).
This double-rail system is a quick and effi-
cient way to image anterior sextants when
one is having difficulty in imaging the ante-
rior with the single-rail system. Because of
the increased number of images, there can
be an increase in error propagation.
FULL-ARCH IMAGING
Full-arch imaging with Omnicam can be
accomplished efficiently by employing
the single-rail system. The key point
that one must understand is that when a
model is created and extended, there will
always be a small degree of error propaga-
tion. To minimize the error propagation,
one should not start at the terminus of
one arch and image to the other terminus.
Rather, one must split the arch in half
and stitch the two halves together. In this
fashion, we have essentially reduced the
error propagation in half.
Imagine a single-rail on the facial of the
anterior sextant andon theocclusal surface
of the posterior arch (Figs. 8-9). Imaging
should be started on the canine area to
allow for rotation over the incisal edge. It
is best to start at this position to capture
the cingulum of the canine. Imaging of the
anterior sextant from point 1 to point 2 is
accomplished. At point 2, one must image
the posterior segment where we incorpo-
rate the buccal and lingual roll of the teeth
while moving along the rail to point 3. At
the terminus of the quadrant, one can hold
the Omnicam on the lingual and move it
along the linguals of the teeth to point 4.
At this point, onemoves to image the other
posterior sextant while moving along the
rail to the terminus at point 5.
Substitution of the single rail in the ante-
rior sextant can be done with the double-
rail system.
BUCCAL BITE
Buccal bite is the registering of the bite
so as to allow for the correct relationship
of the maxillary and mandibular arches.
The discussion for buccal bite must
center on:
1. Where to take the buccal bite
2. How to take the buccal bite
3. How large to make the buccal bite
Thefirst thing to illustrate ishow“where
we take the buccal bite” affects the occlusal
7
8 9
Fig. 7: Double rail
Fig. 8: Maxilla single rail
Fig. 9: Mandible