Seat and position the patient. Positioning varies
according to the type of radiographic examination and
the film placement technique you are going to use.
Specific positioning procedures will be discussed later.
If the patient is a woman, ask her if she is
pregnant. If she is or you suspect that she might be,
consult the dentist.
Ask the patient to remove eyeglasses, complete
dentures, removable partial dentures, earrings, or any
other objects about the head and neck.
Explain the X-ray procedures to the patient. If
the patient is nervous about being X-rayed, explain the
safety precautions taken to prevent overexposure to
Drape the patient with a lead apron and
Quickly examine the patient's mouth to
determine its anatomy. Such things as a small mouth, an
abnormally shallow vault, crooked teeth, and bony
protrusions can affect the placement of the film packet.
The patient's overall bone size and density will
determine the kVp setting. For a patient with a normal
bone size and density, use a kVp setting of 87; for a
patient with a thick bone size and density, use a 90 kVp
Position the patient's head securely against the
Place the film packet in the patient's mouth. Film
placement procedures will be discussed later.
Occasionally patients may gag when the film is placed
in their mouth. The gagging reflex may be caused by
nervousness, so remain calm and reassure the patient.
You might recommend that patients breathe through
their nose, since it is difficult to gag while doing so,
having patients rinse out their mouth with cold water
may also help or have patients concentrate on
something other than gagging. Whatever technique you
use you will have to be swift in placing the film and
making the exposure because the chance of keeping the
gag reflex from returning for an extended period is
After the X-ray procedure is completed, you
must store the lead apron and thyroid collar properly to
avoid damage as shown in figure 1-8.
A periapical examination is conducted to obtain
radiographs of the crowns, roots, and supporting
Figure 1-8.Properly stored lead apron with thyroid collar.
structures of the teeth. Figure 1-9 shows a typical
There are two techniques available to take
periapical radiographs: paralleling and bisecting-
angle. Both techniques use the long axis of the tooth as
a focal point. The paralleling technique is the preferred
method and the bisecting-angle technique is used as an
alternative. Film placement and techniques are
discussed in the following sections.
When using the paralleling technique, you must
center the X-ray film packet behind, and parallel with
Figure 1-9.-Typical periapical radiograph.