Current Concepts in Etiology of Caries

7/28/2019 Current Concepts in Etiology of Caries

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Dr.M.Ganesh,MDS(PediatricDentistry)

CURRENT CONCEPTS INDENTAL CARIES


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CARIES IS.. Dynamic process of de-mineralization and

re-mineralization Complex, multi-factorial disease


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KEYES TRIAD

Interaction of 3 primary factors(Keyes,1960)

Susceptible host

Cariogenic micro flora

Local substrate


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The host-tooth

Composition-Surface enamel resistant

More mineralLess carbonate & water

Morphology-

Enamel hypoplasiaDeep fissures Position-

Alignment


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Microbiology of caries

Caries- infectious disease Streptococcus mutans Streptococcus sobrinus Lactobacillus acidophilus

Actinomyces- root caries


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Virulence traits of S.mutans

Acidogenicity- produce weak acids asby-products of carbohydratemetabolism

lactic acid acetic, formic, propionic, butyric acids

Aciduricity- acid tolerance Proteolysis


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Virulence traits Produces extra-cellular polysaccharides

Mediates irreversible accumulativeadhesion

Increases plaque thickness Intracellular polysaccharides synthesis

Acid production in reduced substrate

availability Maintains acidogenecity & fosters de-

mineralisation in low salivary secretion


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Window of infectivity Caufield,1993

19-31 months

6-12 years


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Substrate (Diet): Readily fermentable Sucrose (table sugar)- Arch criminal


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Cariogenicity determined by

Frequency of ingestion


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Chemical composition-detergency

Cows milk (cheese) contains calcium,phosphorus, and casein

Wholegrain foods require more chewing Peanuts, hard cheeses, and chewing gum Black tea extract

Presence of other constituents


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Physical form

Dried fruit and honey should not beeaten frequently

Soft drinks, sport drinks and fruit juice
http://en.wikipedia.org/wiki/Image:Gatorade_Xtra.jpg


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http://en.wikipedia.org/wiki/Image:Gatorade_Xtra.jpg


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Isolate sugar factors

Identification of foodcausing oral diseases

Code by two colors Taking it as a game for

children Total number of exposures

Exposure- Eating food at onetimeTime of exposure to acid=total exposure x 20 minutes


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Suggest substitutes for food items


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DETERMINE THE ADEQUACY OF DIET

FOOD GUIDE PYRAMID


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Substrate

Readily fermentable Sucrose- arch criminal Cariogenicity determined by

Frequency of ingestion Physical form

Chemical composition-detergency Route of administration Presence of other constituents


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Environment:

Saliva- Composition Flow rate Buffer capacity

Dental plaque


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De-mineralisation & Re-mineralisation:

Caries is a dynamic disease

Loss of mineral replacement

Surface enamel functions as a diffusion matrix

Normally equilibrium exists


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Surface enamel functions as a diffusionmatrix


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Concept of critical pH

pH of saliva 7.0 + 0.4

Early concept : pH at which saliva was no longer saturated

with respect to calcium & phosphate ions,thereby permitting hydroxyapatite todissolve.


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Concept of critical pH (contd)

Plaque fluid: aqueous phase of plaque which forms the interphase

between enamel crystals & their environment &constitutes the milieu in which plaque microorganismsgrow & metabolizePlaque fluid is involved in demineralizationBetween pH 5-6, saliva & pf cease to be saturated,

average 5.5pH safe for teeth is 5.7

Unionized lactic acid molecules diffuse morereadily into enamel; increases as pH falls demineralization


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Concept of critical pH (contd)

Present concept: pH at which the environment of enamel

becomes unsaturated and in addition that

pH at which sufficiently highconcentrations of un-ionized acid arepresent to ensure the inward diffusion ofenough acid to extend to the inner

lesion Lactic acid brings about subsurfacedemineralization


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Thank You

Current Concepts in Etiology of Caries

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