THEORIES OF DENTAL THEORIES OF DENTAL CARIESCARIES

Rubab HaiderRubab HaiderFinal year BDSFinal year BDS

FMH college of MED and DentistryFMH college of MED and DentistryLahore.Lahore.

DENTAL CARIESDENTAL CARIES

--Progressive bacterial damage --Progressive bacterial damage to teeth exposed to saliva.to teeth exposed to saliva.

--one of the most major causes --one of the most major causes of all diseases and major of all diseases and major cause of tooth loss.cause of tooth loss.

--ultimate effect-to breakdown --ultimate effect-to breakdown enamel and dentin and open a enamel and dentin and open a path for bacteria to reach pulp.path for bacteria to reach pulp.

Consequences-inflammation of Consequences-inflammation of pulp and periapical tissues.pulp and periapical tissues.

AETIOLOGYAETIOLOGY

Four major factors involved in Four major factors involved in etiology:-etiology:-

Cariogenic bacteriaCariogenic bacteria Bacterial plaqueBacterial plaque Susceptible tooth surfaceSusceptible tooth surface Fermentable bacterial substrate Fermentable bacterial substrate

(sugar)(sugar)

THEORIES OF DENTAL THEORIES OF DENTAL CARIESCARIES

Chemical (acid) theoryChemical (acid) theory

Parasitic (septic) theoryParasitic (septic) theory

The Acidogenic theoryThe Acidogenic theory

The Proteolytic theoryThe Proteolytic theory

Proteolysis chelation theoryProteolysis chelation theory

CHEMICAL (ACID) CHEMICAL (ACID) THEORYTHEORY In 17In 17thth and 18 and 18thth century,there century,there

emerged a concept that teeth are emerged a concept that teeth are destroyed by acids formed in the destroyed by acids formed in the oral cavity by fermentation of oral cavity by fermentation of food particles around the teeth..food particles around the teeth..

PARASITIC (SEPTIC) PARASITIC (SEPTIC) THEORYTHEORY Microorganisms were associated Microorganisms were associated

with the carious process...with the carious process...

ACIDOGENIC THEORYACIDOGENIC THEORY

W.D Miller was the first well known W.D Miller was the first well known scientist and investigator of dental caries scientist and investigator of dental caries and published his results in 1882.and published his results in 1882.

According to him dental decay is a According to him dental decay is a chemoparasitic processchemoparasitic process

It is a two stage process there is It is a two stage process there is decalcification of the enamel which also decalcification of the enamel which also results in the destruction of the dentin. in results in the destruction of the dentin. in the second stage there is dissolution of the second stage there is dissolution of the softened residue of the enamel and the softened residue of the enamel and dentin. dentin.

ACIDOGENIC THEORYACIDOGENIC THEORY

In the first stage there is In the first stage there is destruction is done by the acid destruction is done by the acid attack where as the dissolution of attack where as the dissolution of the residue is carried by the the residue is carried by the proteolytic action of the bacteria's proteolytic action of the bacteria's

This whole process is supported by This whole process is supported by the presence of carbohydrates the presence of carbohydrates microorganisms and dental plaque microorganisms and dental plaque

PROTEOLYTIC PROTEOLYTIC THEORYTHEORY

PROTEOLYTIC THEORYPROTEOLYTIC THEORY

The evidence given by the acidogenic The evidence given by the acidogenic theory was considerable but it was theory was considerable but it was not conclusive, and alternative not conclusive, and alternative explanation was given in the form of explanation was given in the form of proteolytic theory.proteolytic theory.

Workers like “Heider, Bodecker Workers like “Heider, Bodecker (1878)and Abbott (1879) contributed (1878)and Abbott (1879) contributed considerably to this theory considerably to this theory

PROTEOLYTIC PROTEOLYTIC THEORYTHEORY There has been evidence that the There has been evidence that the

organic portion of the tooth plays an organic portion of the tooth plays an important role in the development of important role in the development of dental cariesdental caries

The are some enamel structure which The are some enamel structure which are made of the organic material such are made of the organic material such enamel lamelle and enamel rodsenamel lamelle and enamel rods

These structure prove to be the path These structure prove to be the path ways for the advancing microorganisms.ways for the advancing microorganisms.

PROTEOLYTIC PROTEOLYTIC THEORYTHEORY It has been established that enamel contains It has been established that enamel contains

0.56 % of organic matter of which 0.18% is 0.56 % of organic matter of which 0.18% is keratin and 0.17 % is a soluble protein keratin and 0.17 % is a soluble protein

Microorganisms produce proteolytic Microorganisms produce proteolytic enzymes,which destroy the organic matrix of enzymes,which destroy the organic matrix of enamel,loosening the apatite crystals….so enamel,loosening the apatite crystals….so they are eventually lost and tissue they are eventually lost and tissue collapses…collapses…

PROTEOLYSIS PROTEOLYSIS CHELATION CHELATION

THEORYTHEORY

PROTEOLYSIS PROTEOLYSIS CHELATION THEORYCHELATION THEORY

Some of the minor flaws of the Some of the minor flaws of the acidogenic and the proteolytic acidogenic and the proteolytic theory were addressed in the theory were addressed in the proteolysis chelation theory.proteolysis chelation theory.

This theory was put forward by This theory was put forward by Schatz and his co-workers in Schatz and his co-workers in 1955.1955.

PROTEOLYSIS PROTEOLYSIS CHELATION THEORYCHELATION THEORY

CHELATIONCHELATION It is a process in which there is It is a process in which there is

complexion of the metal ions to complexion of the metal ions to form complex substance form complex substance through coordinate covalent through coordinate covalent bond which results in:bond which results in:

poorly dissociated /orpoorly dissociated /or weakly ionized compoundweakly ionized compound

PROTEOLYSIS PROTEOLYSIS CHELATION THEORYCHELATION THEORY

Example of chelation reaction:Example of chelation reaction: Hemoglobin in which 4 pyrrole nuclei are Hemoglobin in which 4 pyrrole nuclei are

linked to iron by a similar bondlinked to iron by a similar bond Chelation is independent of the PH of the Chelation is independent of the PH of the

medium.medium. The bacterial attack on the surface of the The bacterial attack on the surface of the

enamel results in the breakdown of the protein enamel results in the breakdown of the protein ,chiefly keratin and results in the formation of ,chiefly keratin and results in the formation of soluble chelates with calcium which decalcify soluble chelates with calcium which decalcify enamel even at neutral PH..enamel even at neutral PH..

Mucopolysaccarides may also act as Mucopolysaccarides may also act as secondary chelators.secondary chelators.

Dental cariesDental caries

Its clinical Its clinical correlationcorrelation

TYPES OF DENTAL TYPES OF DENTAL CARIESCARIES

Gv blanks classification of caries Gv blanks classification of caries classclass

I , II , III , IV , V and VII , II , III , IV , V and VI Rampant caries Rampant caries Recurrent cariesRecurrent caries Arrested cariesArrested caries Root or cemental cariesRoot or cemental caries Baby bottle caries Baby bottle caries

Pits and fissure cariesPits and fissure caries

Proximal cariesProximal caries

Cervical cariesCervical caries

Rampant cariesRampant caries

Recurrent cariesRecurrent caries

Arrested cariesArrested caries

Root or cemental Root or cemental cariescaries

Nursing bottle cariesNursing bottle caries

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