Transcript 02. The epidemiology of dental diseases

The epidemiology of common dental diseases in
children. Epidemiological studies in dentistry,
accounting methods and forms.
Radiographs
Bitewing Film primarily used.
Periapical film also used
There is a lot of discussion on which film
speed (D or F) should be used. Many
dentists use D-speed film because they feel
it provides better diagnostic images as a
result of the smaller grain size. Most
educators, on the other hand, recommend
the F-speed film (Insight) because of the
significant reduction in x-ray exposure to
the patient (approximately 60% less).
Proximal caries susceptible zone
caries
Approximately 50 % demineralization is required for
radiographic detection of a lesion. As seen in the
occlusal view, above right, the thickness of the tooth
buccolingually masks the carious lesion when it is
small.
The actual depth of penetration of a carious lesion
is deeper clinically than radiographically.
Factors affecting appearance of caries:
Buccolingual thickness of tooth. The
thicker the tooth, the more difficult it is to
see the extent of the caries.
Two-dimensional film. Cannot see the
extent of carious involvement in a
buccolingual direction.
Factors affecting appearance of caries:
X-ray beam angle (horizontal or vertical).
This is especially important when trying to
identify recurrent caries, since changes in
angulation may cause the superimposition
of the existing restoration with the carious
lesion.
Exposure factors. Caries detection is
improved with a lower kVp setting, which
provides a higher contrast. If the density of
the film is too light or too dark, the
diagnostic potential of the film is limited.
Caries Classification
I
M
A
A
I = Incipient (Stage I)
M = Moderate (Stage II)
A = Advanced (Stage III)
S = Severe (Stage IV)
S
Unless fairly large, interproximal
caries in the posterior region
usually requires radiographs to
make a diagnosis. In the anterior
region, interproximal caries can
often be diagnosed using
transillumination, which involves
directing a bright light through the
contact areas.
Interproximal Caries
(Incipient)
I
Up to half the thickness of enamel
Usually not restored unless patient
has high level of caries activity (high
risk). Treat with fluoride.
The arrow points to incipient lesions on the
mesial of # 19 and the distal of # 20.
Incipient
Moderate
Advanced
Interproximal Caries
(Moderate)
M
More than halfway through the
enamel (up to DEJ)
The bottom arrow points to a moderate lesion
on the distal of # 20. The upper arrow points to
one of several incipient lesions on the molar
and premolars.
Moderate lesion seen on previous film
Class III moderate lesion seen in the
anterior region
Interproximal Caries
(Advanced)
A
A
Advanced lesion identified by arrows.
Advanced lesions seen on previous film
Advanced lesion
Advanced lesion
Interproximal Caries
(Severe)
S
More than halfway
through the dentin
Severe lesion
Severe lesion
Occlusal Caries
Must have penetrated into dentin
Diagnosed from clinical exam
May be seen as thin radiolucent line or
cup-shaped zone underlying occlusal
enamel, but difficult to see on
radiographs unless lesion is large.
Some feel that a sharp explorer used too
forcefully may contribute to spread
of caries by opening up pit or fissure
Occlusal caries
Occlusal caries
Buccal/Lingual
Caries
Should be identified from clinical
exam. Sometimes seen as welldefined circular area in middle of
tooth, although it is not very
radiolucent. Depth can not be
determined radiographically.
Lingual caries (Can’t tell whether it’s buccal
or lingual from one radiograph
Buccal caries with severe interproximal
caries on # 12
Root Caries
Saucer-like cratering on the roots of the
teeth, involving the cementum. Usually
found on older individuals with
prominent recession and/or
periodontitis. May have xerostomia due
to medications. May be confused with
cervical burnout (discussed on later
slide).
Root caries
Root caries
Cervical Burnout
Cervical burnout is an apparent radiolucency
found just below the CE junction on the root
due to anatomical variation (concave root
formation posteriorly) or a gap between the
enamel and bone covering the root
(anteriorly). Mimica root caries. Posteriorly,
this radiolucency usually disappears when
another film of the region is examined. Caries
does not occur on the root of the tooth unless
there is loss of alveolar bone and gingival
tissue due to recession or periodontitis.
Posterior cervical burnout. The invagination
of the proximal root surfaces allow more xrays to pass through this area, resulting in a
more radiolucent appearance on the
radiograph. X-rays directed at a different
angle usually pass through more tooth
structure and the radiolucency disappears.
Radiolucency seen at left (arrow)
disappears on periapical film of
same tooth. This is cervical burnout.
Anterior cervical burnout. The space between
the enamel and the bone overlying the tooth
will appear more radiolucent than either the
enamel or the bone-tooth combination.
bone level
Cervical burnout in the
anterior region due to
gap between enamel
(red arrows) and
alveolar bone over root
(blue arrows).
Recurrent Caries
Found around the margins of existing
restorations. May be due to unusual
susceptibility to caries, poor oral
hygiene, failure to remove all of the
caries during cavity preparation, a
defective restoration or a combination
of the above.
Recurrent caries
Recurrent caries
Recurrent caries
Rampant Caries
Extensive and rapidly progressing
caries usually found in children
and teens with poor diet and
inadequate oral hygiene
Radiation Caries
Found in head/neck radiation
therapy patients with xerostomia
Fluoride used for control
Before radiation
1 year after radiation
Mach Band
Optical illusion giving appearance of
increased radiolucency at the junction of
differing tissue densities, such as enamel
and dentin. If you block off the enamel with a
fingernail, the radiolucency will disappear if
due to the mach band effect. If the
radiolucency persists, it may be caries.