Caries Diagnosis and Progression

7/28/2019 Caries Diagnosis and Progression

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It is an irreversible microbial disease of calcified tissue of teeth characterized bydemineralization of inorganic portion and

destruction of organic substance of the toothwhich often lead to cavitation.



According to location:a) pit and fissure

b) Smooth surface

c) Root surface

Acc. to structure of tooth:

a) Enamel

b) Dentine

c) Cementum



Onset and progression:

a) Acute

b) Chronic

c) Incipient

Acc. To chronology:

a) Infancyb) Aldosencent

c) Adult

Acc. to senile:

a) Rampant

b) Arrested



The Early Theories :

I. The legend of worm.

II. Endogenous theories

III. Chemical theory

IV. Parasitic theory



It states that caries is caused by ACIDproduced by microorganisms of the mouth.

Dental decay is a CHEMOPARASITIC PROCESSconsisting of two stages :

I. Decalcification of enamel and dentine (

preliminary stage ).II. Dissolution of the softened residue (

subsequent stage ).



Acids resulting in primarydecalcification is produced byfermentation of starches and sugar

from the retaining centers of teeth.

Significance of Miller’s observation

included three factors namely :1. Oral microorganisms.

2. Carbohydrate substrate.

3. Acid produced by themicroorganisms.



ZONES OF ENAMEL CARIES:

Zone 1:Translucent zone (TZ): First recognizable zone of the lesion. Advancing front of the lesion . Half the lesions demonstrate TZ ,not always

present.

TZ appears structure less. Pore volume -1% (compared to 0.1% sound enamel)

Zone 2: Dark zone:

Lies adjacent and superficial to the TZ . Positive zone. Shows positive birefringence (in contrast to sound

enamel)

Pore volume of 2%-4% (polarized light )



Presence of small pores,large molecules of quinolone are enable to penetrate.

Micropore system –gets filled with air and becomedark.

Medium like water may penetrate.

Zone 3:Body of lesion Between unaffected surface and dark zone.

Area of greatest demineralization .

Pore volume -5% in periphery and 25% in centre.

Water imbibition- positive birefringence compareto sound enamel.

Striae of retzius -prominent



Zone 4: surface zone

Quantitative studies –partial demineralization of 1-10%.

Pore volume –less than 5% of spaces.

Negative birefringence-water imbibition.

Positive birefringence-porous subsurface.



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Dentinal caries starts from DEJ andinvolves greater number of dentinaltubules.

It includes following stages namely :

1. Early dentinal changes.

2. Advanced dentinal changes.

3. Secondary dentine involved.



Caries penetrate initial to dentine. Ground section shows TRANSPARENTappearance of tooth surface in

transmitted light. Reflected light shows SCLEROTICdentine, which will appear dark.

Fatty degeneration of TOME’S fibers.

PIONER bacteria in early stages of caries is seen.



Here, decalcification of tubule wall,

liquefaction of foci is seen. Globular dentine also showsdecalcification.

Proteolytic enzyme produced bymicroorganisms cause furtherdestruction.

Lathery consistency of necrotic massis seen.



Zone 1 : Zone of fatty degeneration of

Tome’s process. Zone 2 : Zone of dentinal sclerosis.

Zone 3 : Zone of decalcification of

dentine. Zone 4 : Zone of bacterial invasion of decalcified but intact dentine.

Zone 5 : Zone of decomposeddentine.



The caries involvement of secondarydentine is usually slower because thedentinal tubules are fewer in number

and more irregular in their course,thus delaying the penetration of theinvading microorganisms.

Occasionally, caries will spreadlaterally at the junction of the primaryand secondary dentine and produces aseparation of two layers.





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Caries Diagnosis and Progression