3-2 SM700_K2100_03_en 9/2007
Figure 9. Paralleling technique (left) and Bisecting technique (right)
Positioning the imaging receptor
Using the KODAK 2100 Intraoral X-ray System, you may create an x-ray
image on one of three different types of imaging receptors:
• Conventional silver halide films, such as KODAK INSIGHT or
KODAK ULTRA-SPEED dental films
• Digital sensors, such as KODAK RVG sensor
• Phosphor plate
Properly placing the receptor is critical. Check your dental radiography text
for information about proper placement of the imaging receptor.
Improperly positioning the film or sensor results in errors on the radiograph,
such as distorted teeth and roots, elongation, magnification, and/or
overlapping contacts. The paralleling technique generally reduces the risk of
such errors. However, if you improperly position the system, angulation
errors can occur (angulation of the receptor to the tooth itself).
If the exit pattern of the beam is not aligned with the imaging receptor, then
part of the radiograph will not be exposed to radiation and the final
radiograph will have some clear (unexposed) areas. This defect is called
“cone cuts”.
The imaging receptor is marked to indicate the tube side. If the orientation is
not correct, the resulting radiograph is lighter and may show artifacts, such as
foil pattern or sensor cable.
Exposure
Exposure parameters
Because each receptor (film, digital sensor, or phosphor plate) has its own
sensitivity to x-ray radiation, the choice of receptor affects the exposure
parameters. For instance, sensitivity class for conventional dental films is
characterized with a letter D, E, or F where F is more sensitive than E, and E
more sensitive than D. Consequently, the required dose for the correct
exposure goes down with each increase in sensitivity.
Tables with recommended exposure times are found in Section 6. The
exposure times are based on manufacturers’ recommendations. The table
should be considered as a guideline; adjust to accommodate your conditions.
Adjust the exposure time range based on the type of receptor you use, film or
digital. To change the mode, press and hold the selection knob at least
3 seconds. Then turn the selection knob to set the exposure time.
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