July 1st, 2009 by admin

The diagnosis of caries requires
good lighting
and
dry, clean teeth
. If deposits
of calculus or plaque are present, the mouth should be cleaned before attempt-
ing accurate diagnosis. Remember to brush plaque out of the fissures because it
is easy to miss a white spot lesion at the entrance to a fissure unless the surface is
clean (Figure 3.2). Do not remove plaque automatically, without thinking. After
all, the process occurs within the plaque. Its presence or absence will be relevant
to your decision about the activity of the lesion.
When the teeth have been cleaned, each quadrant of the mouth is isolated
with cotton wool rolls to prevent saliva wetting the teeth once they have been
dried. Thorough drying should be carried out with a gentle blast of air from
the three-in-one syringe. White spot lesions are more obvious when teeth are
dry (see page 29) and saliva can even obscure small cavities.
Sharp eyes
can be used to look for the earliest signs of demineralization.
Sharp probes should never be used to detect the ‘tacky’ feel of early cavi-
tation, because a probe can damage a white spot lesion (see Figure 2.9)
creating a hole which will subsequently trap plaque.
Good
bitewing radiographs
are also essential in diagnosis. In this tech-
nique the central beam of X-rays is positioned to pass at right angles to the
long axis of the tooth, and tangentially through the contact area. The film is
positioned in a film holder on the lingual side of the posterior teeth. The
patient then closes the teeth together on the film holder