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 micro-organisms). 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 micro-organisms).
-initial penetration of the dentin by caries dentinal sclerosis,
-calcification of dentinal tubules and sealing off from further penetration by
-more prominent in slow chronic caries.
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.
-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.
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
Shape of the lesion is triangular with the apex towards the pulp and the base towards the enamel.
Zone 1; Zone of Fatty Degeneration of Tome’s Fibers,(next to pulp)
-due to degeneration of the odontoblastic process. This occurs before sclerotic dentin is formed and makes the tubules impermeable.
-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 to acids and enzymes.
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.
-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 involvement.
-the rate is slower due to fewer dentinal tubules than crown area
Importance of early caries detection
Identifying lesions requiring surgical treatment
Identifying lesions requiring non-surgical treatment
Persons at high risk for developing caries
Thus diagnosis is done using:
Newer refined diagnostic tools
Most widely used method, in dental offices, in clinical research and in epidemiological studies.
The purpose of the radiograph is to detect lesions that are clinically hidden from careful visual examination.
When radiography is applied in the clinic for caries detection, the recommended technique is bitewing projection (Gröndahl, 1994).
Not convincingly able to distinguish between cavitated and noncavitated surfaces (Nielsen et al., 1996)
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
Twice as sensitive as conventional D-speed films
“Edge enhancement”is possible
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.
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
The observation can be qualitative or quantitative.
Dyes should be
-safe for intra-oral use
-stain the tissues that are diseased
-should be easily removedDYES USED FOR CARIES DIAGNOSIS
Vista red, Vistadental
Carious Enamel: Procion, Calcein, Brilliant Blue is used.
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.
Caries detecting dyes stain infected carious dentin, but also stain the demineralized organic matrix of carious dentin, which should not be removed.
A. Initial bacteria
B. Frontier bacteria
C. Pioneer Bacteria
D. Premier bacteria
A. slowly progressing caries
B. Acute caries
c. Incipient caries
D. irreversible caries
A. Advanced caries
B. Initial caies
C. Rampant caries
D. Incipient caries
A. Predominantly acidogenic bacteria
B. Proteolytic bacteria
C. Premier bacteria
D. acidophillic bacteria
A. Zone 1
B. Zone 2
C. Zone 3
D. zone 4
a. Visualising perapical area
b. Proximal caries
c. Occlusal caries
d. Root caries
a. proximal caries
b. occlusal caries
c. root caries
d. enamel caries