Dental Caries
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Dental Caries

Caries And Restorative Dentistry

Pedodontics

DENTAL CARIES

Contributed By: Dr. Amit Borse

 

DEFINITION : INFECTIOUS, COMMUNICABLE DISEASE RESULTING IN DESTRUCTION OF TOOTH STRUCTURE BY ACID FORMING BACTERIA PRESENT IN DENTAL PLAQUE IN PRESENCE OF SUGAR.


THEORIES :

1. Worm theory : According to this theory toothache is due to worm ingestion which drank blood of tooth as a punishment for offenses against god.

2. Humors theory: Caries cause due to imbalance in humors.

3. Vital theory: Caries originate like bone gangrene from within the tooth.

4. Chemical theory: Teeth were destroyed by acid formed in oral cavity like sulfuric acid ,nitric acid. Citric acid formed by decomposition of food in saliva.

5. Septic theory: Caries develop as a result of infiltration & decomposition of enamel cuticle , the inter prismatic substance of enamel & finally dentin.

6. Acidogenic theory:  1890 W.D.Miller

Also called as CHEMICOPARASITIC THEORY. In presence of carbohydrates, microorganisms & dental plaque on tooth surface - proteolysis takes place - forming acid - resulting into decalcification of enamel, destruction of dentin & dissolution of softened residue of enamel & dentin - resulting in dental caries .

7. Proteolysis theory: Gottlieb 1944

 According to this, protein component of tooth structure is destroyed first prior to loss of tooth minerals due to proteolysis as described by W.D.Miller. Enamel rods, lamellae are the organic pathways for organisms and cause destruction of them.

8. Proteolysis Chelation  theory: Schatz & Martin 1955

Extensions of proteolysis theory. Microbial degradation of organic components (proteolysis )--- results into ----dissolution of minerals of tooth by process of chelation.

9. Autoimmune theory: Jackson and Burch

“Genetic structure of a person is responsible for caries susceptibility or caries immunity.”


ETIOLOGY: KEYES Triad

  1. Tooth (host)
  2. Substrate (fermentable carbohydrate )
  3. Microorganisms( bacteria- viz. Strep. Mutans)

 2 more factors were added

  1. Time
  2. Saliva: flow rate, Buffering capacity, pH, composition.

CRITICAL pH: critical value of 5.5

“It is the pH at which environment of the enamel becomes unsaturated and in addition that pH at sufficiently high concentration of an ionized acid are present to ensure the inward diffusion of enough acid to extend to inner lesion.”

WINDOW OF INFECTIVITY: 19-33 months of age; mean- 26 months

Mutans streptococci require hard surface for colonization . Hence , presence of teeth is required for microorganisms to attack ,proliferate &multiply known as period of ‘WINDOW OF INFECTIVITY‘.

Microflora related to Dental Caries :

  1. Pit& fissure: S.mutans, S.sanguis, lactobacilli species, actinomyces species
  2. Smooth Surface: S.mutans, S.salivarius
  3. Root surface: A.viscosus, A.naeslundii, S.mutans, S.sanguis.
  4. Deep Dentinal Caries: Lactobacilli species , A.naeslundi, other filamentous rods.

Zones of Enamel & Dentin lesion :

Enamel

  1. Translucent zone
  2. Dark zone
  3. Body of lesion
  4. Surface lesion

Dentin-  Zone of

  1. Fatty degeneration of Tome’s fibers
  2. Dentinal sclerosis
  3. Demineralization of dentin
  4. Bacterial invasion
  5. Decomposed dentin

TRISTAN DA CUNHA: FISHER 1986

Volcanic eruptions in island - population moved to England 1962

Dental examination in 1962 & on returning in 1966 carried out.

1962 - Simple diet and caries in 1st molar in 6-19 years aged equal to 0.

1966 - Caries increased to 50% due to diet and was same as that was in England at that time.

Reference : Book of Paediatric Dentistry-S.G.Damle, 4th edition

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