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Radiographic Caries Identification
developed by Dr. Joen Iannucci DDS, MS
Although many carious lesions are easily seen clinically or radiographically, others may
be very difficult to identify. Studies have indicated that there are significant
variations among dental professionals regarding the radiographic interpretation of dental
In order to detect dental caries, both
careful clinical and radiographic examinations are necessary. The focus of this web
resource is RADIOGRAPHIC
CARIES IDENTIFICATION and includes the
RADIOGRAPHIC CLASSIFICATION OF
FACTORS INFLUENCING CARIES
CONDITIONS RESEMBLING CARIES
Following these introductory topics, there
is an opportunity to view radiographs and test your skill in identifying dental caries.
|C A R
I E S D E T E C T I O N
dental examination for caries cannot be considered complete without radiographs. The
dental radiograph enables the dental professional not only to evaluate the extent and
severity of a carious lesion seen clinically, but also to identify carious lesions that
are not visible clinically. In order to establish a diagnosis and develop
treatment decisions, information is needed from the clinical examination,
radiographic examination and patient history.
|All teeth must be examined clinically for dental
caries. The dental professional should have a set sequence for the caries
examination. The examination should begin with tooth #1, followed by tooth #2, #3,
etc., and end with tooth #32. All exposed and accessible surfaces should be examined
for dental caries. All positive and suspicious clinical findings should be
documented in the patient record and evaluated with dental radiographs.
|In order to ensure good visibility, a bright
operatory light should be used in the clinical examination. A mirror and explorer
can be used to examine the teeth for evidence of dental caries. The mirror can be
used to reflect light, to allow for indirect vision and to retract the tongue. The
explorer can be used judiciously as a tactile device to detect the presence of any consistency changes
(e.g., catches or tug-back) in the pits, fissures and grooves of the
teeth as well as cavitation or break in the enamel of smooth surface
|Compressed air can be used to dry teeth and remove
debris in order to allow for a better visual examination. A small flashlight can be
used to detect dental caries on anterior teeth. Trans-illumination, or
the passage of light through the tooth, allows the clinician to determine if the enamel is
healthy. When the anterior teeth are illuminated with light, healthy areas of enamel
permit the passage of the light while areas involved with dental caries do not.
Clinically, a number of
color changes may be seen with dental caries. Occlusal surfaces may exhibit dark
staining in the fissures, pits and grooves, or exhibit a gross, or obvious, cavitation.
Smooth tooth surfaces may exhibit a chalky white spot or opacity indicating
demineralization. A clinician must examine these areas carefully
to determine whether stained areas are also cavitated. An interproximal ridge overlying a carious lesion may also appear
A radiograph of any suspicious area that
exhibits a change in consistency or color can give the practitioner additional information
concerning the extent and severity of the lesion present. In some instances, no
color change, cavitation or consistency changes are noted clinically. It is in these
cases that radiographs play such an important role in the identification of dental caries.
|Radiographs are useful in the detection of
caries because of the nature of the disease process. Demineralization and
destruction of hard tooth structures result in a loss of tooth density in the area of the
lesion. The decreased density allows a greater penetration of x-rays in the carious
area, and as a result, the carious lesion appears as a radiolucency on a
dental radiograph (see red arrows). Radiolucent structures permit the passage of the
x-ray beam and appear dark or black on a dental radiograph.
The degree of radiolucency seen on a dental radiograph is determined by the extent and
severity of the destruction seen as a result of the caries process.
Caries is always farther advanced clinically
than what is seen on a dental radiograph. The early changes associated with
demineralization do not affect the density of the tooth, and consequently, an increased
penetration of the x-ray beam is not seen.
radiograph, a radiograph that shows the crowns of both the upper and lower teeth on the
same film, is the radiograph of choice for the evaluation of dental caries. A
periapical radiograph utilizing the paralleling technique can also be used to detect
interproximal caries. In order for a bite-wing radiograph to be considered
diagnostic for the evaluation of dental caries, the following criteria should be met:
DIAGNOSTIC BITE-WING CRITERIA
Exposure and processing:
Proper film exposure and processing techniques must be used.
Interproximal areas must demonstrate open contacts; a thin radiolucent line should be seen
between the contacts of adjacent teeth (see red arrows on film above).
Occlusal plane: The
occlusal plane should be positioned horizontally along the midline of the long axis of the
Premolar placement: The
premolar bite-wing should demonstrate the distal contact areas of both the maxillary and
The molar bite-wing should be centered over the second molar.
bite-wing should be free of technique errors (e.g., cone cuts, film bending and backwards
placement of a film).
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