Dentaltown November 2022 - 42

Creating and using the CIPC
The calibrated implant pin control (CIPC, Fig. 1)
combined with digital periapical radiography will
guide the pilot osteotomy drill safely to avoid any important
anatomical structures.
It is possible to construct the CIPC by using two
straight handpieces, a latch drill, a heatless stone, a
thin separating corundum disc and a caliper. Shape
the latch drill to match the silhouette of the pilot osteotomy
drill, and form a 1-mm-long, 0.5-mm-wide
tip. Create grooves at sites you select, such as at 5 and
11 mm measured from pin tip along the shaft. Cut
the latch drill to a length of 17 mm and smooth with
a rubber wheel. At the end of the latch drill, create a
groove to attach a long dental fl oss for safety and the
CIPC is now complete. I chose a 17 mm total length
to prevent interocclusal interference as the patient occludes
on the bite plate of the sensor holder.
Using the CIPC to measure osteotomy depth, slip
a small-diameter orthodontic elastometric separator
ring onto the CIPC and, with a straight hemostat, introduce
it into the pilot osteotomy. Adjust the ring to
the entrance of the osteotomy orifi ce for depth length
reference. The ring on Fig. 1 illustrates depth at 9 mm.
With the CIPC in situ, expose a digital periapical radiograph.
This
CIPC procedure is similar to the well-known
root canal pin control, where I use a root canal fi le with
Fig. 1
Calculating magnifi cation distortion
Whether using short or long cone, or bisecting or
paralleling techniques, there are inherent distortion errors
of intraoral periapical radiography. Magnifi cation
discrepancies of foreshortening or elongation will be
present on the views of the screen. However, because
the 1-mm-long tip of the CIPC in the pilot osteotomy
will suffer the same magnifi cation error as the distortion
of the immediate intraosseous surrounding anatomy,
the distance from the end of that 1-mm CIPC tip
to the nearby vital anatomy will receive the same magnitude
of magnifi cation distortion. This dimensional
change will alter the tip of the CIPC to the same degree
that it will affect the short distance from that end to
the nearby vital structure. This permits calculating the
distances to negotiate tight intraosseous spaces for the
implant osteotomy and to avoid critically important
anatomical landmarks.
42 NOVEMBER 2022 // dentaltown.com
a small rubber disc, and slide it into the root canal to
determine the root canal length on a periapical radiographic
view.
Determining bucco-lingual relation
Comparison of the digital image of the straight
periapical radiographic view with the mesial and distal
projections is used to determine the bucco-lingual
relation of an object of interest, per Clark's horizontal
tube shift rule.4
When the tube is shifted horizontally,
the object moves in the same direction on the screen if
it is located on the lingual side. For example, when the
pilot osteotomy is near the mental foramen, it can be
directed as to bypass the foramen on the lingual side.
Richard's buccal object rule5
describes vertical tube
shift. When the object of interest is on the buccal side,
it moves in the same direction as the X-ray beam is directed.
For example, the inferiorly directed beam shifts
the buccally located inferior alveolar canal apically, related
to the tip of the CIPC on the screen. Similarly,
the coronally aimed beam moves the buccally located
object on the view coronally, closer to the CIPC.
The benefi t of using the CIPC is that the tip of
the pin is at the same location as the pilot drill tip in
the osteotomy. Knowing the calibrations of the CIPC,
the exact distance measurements are obtained in actual
millimeters to a vital structure by using the software
length measurement on the screen.
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Dentaltown November 2022

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