Transcript Dental Caries- Histoplathology

Dental Caries- Histoplathology
Dr. Rhythm
Assistant Professor
• CARIES OF DENTIN
• Begins with the natural spread of the
process along the DEJ and rapid
• involvement of the dentinal tubules.
The dentinal tubules act as tracts
leading to the pulp (path for microorganisms).
Caries of Dentin
• Early Dentinal Changes:
• -initial penetration of the dentin by
caries dentinal sclerosis,
• -calcification of dentinal tubules and
sealing off from further penetration by
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micro-organisms,
• -more prominent in slow chronic caries.
In the earliest stages, when only few tubules
are involved, microorganisms may be found
penetrating the tubules Pioneer Bacteria.
This initial decalcification
involves the walls allowing
them to distend as the
tubules are packed with
microorganisms. Each tubule
is seen to be packed with pure
forms of bacteria, eg., one
tubule packed with coccal
forms the other tubule with
bacilli.
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Advanced Dentinal Changes ;
-decalcification of walls, confluence of the dentinal tubules,
-tiny “liquefaction foci”, described by Miller are formed by the focal coalescing
and breakdown of dentinal tubules. These are ovoid areas of destruction parallel
to the course of the tubules which filled with necrotic debris and increase in size
by expanding. The adjacent tubules are distorted and their course is bent due to
this expansion.
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As the microorganisms proceed further they are distanced from the
carbohydrates substrate that was needed for the initiation of the caries.
Thus the high protein content of dentin must favour the growth of the
microorganisms. Therefore proteolytic organisms might appear to predominate
in the deeper caries of dentin while acidophilic forms are more prominent in
early caries.
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Shape of the lesion is triangular
with the apex towards the pulp
and
the
base
towards
the
enamel.
Zone
1;
Zone
Degeneration
of
Fatty
of
Tome’s
Fibers,(next to pulp)
-due
to
degeneration
odontoblastic
of
process.
the
This
occurs before sclerotic dentin is
formed and makes the tubules
impermeable.
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Zone
2;
Zone
of
dentinal
sclerosis,
-deposition of Ca salts in the
tubules.
Zone 3; Zone of decalcification
of dentin
Zone
4;
Zone
of
bacterial
invasion
Zone 5; Zone of decomposed
dentin
due
enzymes.
to
acids
and
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Root Caries
• Root caries as defined by HAZEN, is a soft, progressive
lesion that is found anywhere on the root surface that
has lost its connective tissue attachment and is exposed
to the environment.
• -the root surface must be exposed to the oral
environment before caries can develop here.
• -Plaque and micro-organisms are essential for the cause
and progression of the lesion, mostly Actinomyces,
• -micro-organisms invade the cementum either along the
Sharpey’s fibers or between the bundles of fibers.
• -spread laterally, since cementum is
formed in concentric layers.
• -after decalcification of cementum,
destruction of matrix occurs similar to
dentin with ultimate softening and
destruction of this tissue.
• -invasion of micro-organisms into the
dentinal tunbules, finally leading to pulp
Importance of Early Caries
Importance of early caries detection
Detection
• Objectives of diagnosis:
– Identifying lesions requiring surgical treatment
– Identifying lesions requiring non-surgical treatment
– Persons at high risk for developing caries
• Thus diagnosis is done using:
– Clinical criteria
– Tools
– Newer refined diagnostic tools
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VISUAL EXAMINATION
Most widely used method, in dental offices,
in clinical research and in epidemiological
studies.
 Quick, cheap and easy.
 Should be performed on a dry, clean tooth, with good
light, with a mirror.
Wet
Dry
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Role of Magnification in Determining Cavitation
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• Dental floss may be
employed to detect
proximal caries.
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• Sturdevant’s (1985) :
METHOD
– Defects are TACTILE
best detected
when an explorer placed
into a pit or fissure provides tug-back or resistance
to removal.
• Subject of controversy:
– Use of the explorer does not add anything to the
detection yield of the examination.
– The use of the explorer may at best be misleading
and at worst be potentially damaging
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RADIOGRAPHY
The purpose of the radiograph is to detect lesions that are
clinically hidden from careful visual examination.
ADVANTAGES :
– Discloses sites inaccessible to other methods
– Detects at early , reversible stage
– Depth of lesion can be evaluated and scored by index given by
Grondahl et al (1977)
– Permanent record
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BITE WING RADIOGRAPHS
• When radiography is applied in the clinic for caries
detection, the recommended technique is bitewing
projection (Gröndahl, 1994).
Disadvantages
• Not convincingly able to distinguish between
cavitated and noncavitated surfaces (Nielsen et al.,
1996)
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XERORADIOGRAPHY
BY CARLSON 1937
• Image is recorded on an aluminium plate coated with
a layer of selenium particles which have a uniform
electrostatic charge
• X-rays cause selective discharge from the particles,
forming a latent image, which is developed to a +ve
image by developing
Advantages:
• Twice as sensitive as conventional D-speed films
• “Edge enhancement” is possible
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DIGITAL RADIOGRAPHY
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QLF, THE QUANTITATIVE LIGHT INDUCED
FLUORESCENCE METHOD
• The science behind this phenomenon appears to be
the increased fluorescence exhibited by cariogenic
bacterial metabolites within the lesion, as well as the
changed fluorescent nature of the lesion itself.
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ENHANCED VISUAL TECHNIQUES
FIBER OPTIC TRANS-ILLUMINATION( FOTI):
• Principle: decayed matter scatter light more
strongly-lower index of light transmission
• Can be used in all surfaces, particularly useful at
proximal lesions
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DYES USED FOR CARIES DIAGNOSIS
• Dyes can visualize a subject from its routine
background by colour.
• The observation can be qualitative or quantitative.
• Dyes should be
-safe for intra-oral use
-stain the tissues that are diseased
-should be easily removed
Vista red, Vistadental
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DYES IN CARIES DETECTION
Carious Enamel: Procion, Calcein, Brilliant Blue
is used.
• Dentin caries: Basic fuchsin , Methylene blue,
Acid red.
• Modified dye preparation uses iodine.
– It measures enamel porosity in incipient
carious lesions
Bakhos et
al.(1977)
– Uses iodine as potassium iodide.
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DIGITAL RADIOGRAPHY
• A digital imaging is an image formed and
represented by a spatially distributed set of
discrete sensors and pixels
• when viewed from a distance the image
appear continuous, but on closer inspection it
has individual pixels.
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Caries detecting dyes stain infected
carious dentin, but also stain the
demineralized organic matrix of carious
dentin, which should not be removed.
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• Q. 1 Bactria found in initial dentinal caries are
called
• A. Initial bacteria
• B. Frontier bacteria
• C. Pioneer Bacteria
• D. Premier bacteria
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Q.2 Dentinal sclerosis is seen in
A. slowly progressing caries
B. Acute caries
c. Incipient caries
D. irreversible caries
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Q.3 Liquefaction foci can be seen in
A. Advanced caries
B. Initial caies
C. Rampant caries
D. Incipient caries
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Q.4 Early caries is associated with
A. Predominantly acidogenic bacteria
B. Proteolytic bacteria
C. Premier bacteria
D. acidophillic bacteria
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Q.5 Zone of fatty degeneration is
A. Zone 1
B. Zone 2
C. Zone 3
D. zone 4
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Q. 6 Root caries is caused due to
A. Actinomyces
B. Lactobacillus
C. Streptococcus
D. Staphylococcus
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Q.7 QLF is based on
a. Fluorescence
b. Absorption
c. Scatter
d. Radiation
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Q.8 Bite wing radiographs are best for
a. Visualising perapical area
b. Proximal caries
c. Occlusal caries
d. Root caries
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Q.9 Root caries is caused by
a. Actinomyces
b. Lactobacilli
c. Streptococcus
d. Staphylococcus
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Q.10 Dental floss is used for detecting
a. proximal caries
b. occlusal caries
c. root caries
d. enamel caries