etiology in dental caries

Exogenous Theories

> Legend of worm

>Chemical Theory

>Parasitic or Septic Theory

Endogenous Theories

> Humoral theory

> Vital theory

The worm theory

Dates back as far as 5000 BC referenced in a Sumerian text

The worm theory

They believed tooth worm bore a hole through your teeth and hid beneath the surface; drank blood of teeth and fed on roots of jaws.

Exogenous Chemical theory (acid theory)

It was believed that putrefaction of protein led to formation of ammonia which was subsequently oxidized to nitric acid

Robertson 1835

opined that caries was caused by chemical disintegration of the tooth

Exogenous Parasitic or Septic Theory

Ficinus recognized the first organic matrix in enamel

Erdl and Ficinus 1843

filamentous microorganisms caused decomposition of the teeth

Ficinus

___ recognized the first organic matrix in enamel

Endogenous Humoral Theory

Imbalance in this 4 humors determines the person’s physical and mental constitution

blood,

phlegm,

black bile, y

ellow bile

The four elemental fluid (humors) of the body

Endogenous Vital Theory

Postulated that tooth decay originated like bone gangrene from within the tooth itself.

Hippocrates, Celsus, Galen and Auicenna. 18th century.

Endogenous vital theory is propose by whom and when?

Miller 1890

Person in Chemico-Parasitic Theory

Chemico-Parasitic Theory (Miller 1890)

The theory said that caries is caused by acids produced by oral bacteria following fermentation of sugar

1- decalcification of enamel, destruction of dentin (preliminary stage)

2- dissolution of the softened residue of enamel & dentin (subsequent stage)

2 stages of oral bacter sugar fermentation

Heider and Bodecker 1878 and

Abbot in 1879,

Gottlieb 1944

Pincus 1949

Person in proteolytic theory

Proteolytic theory

Said that organic portion of the tooth serves as pathways for advancing microorganisms causing demineralization of the teeth and therefore dental caries.

Proteolytic Theory Gottlieb in 1944

Suggested that the initial lesion of the carious process is due to the proteolytic enzymes attacking the lamellae, rod sheaths, tufts and walls of tubules

Believed that the yellow pigmentation characteristic of caries was produced by the proteolytic organism (Staphylococcus )

Proteolytic Theory Pincus in 1949

Proposed that the first step in the carious process is the breakdown of dental cuticle.

Nasmyth’s membrane and enamel proteins are acted upon by sulfatase enzyme producing sulfuric acid. This acid plus the calcium of hydroxyapatite crystals destroys the inorganic component of enamel

Nasmyths membrane and enamel proteins, sulfuric acid, calcium

___ are acted upon by sulfatase enzyme producing ___. This acid plus the ___ of hydroxyapatite crystals destroys the inorganic component of enamel

Proteolysis- Chelation Theory Schatz 1955

This theory state that dental caries is a bacterial destruction of organic components of enamel and the breakdown products of this components have chelating properties dissolving the minerals in enamel

There is simultaneous microbial degradation of organic component by proteolysis and dissolution of inorganic part by chelation

1.the host (teeth, salive)

2.microflora.

3.substrate(diet).

4.time..

Etiologic factors in dental caries:

Economic status of population

Increasing educational status

Growing number of dental graduates

Insurance programs

Commercial pressure

Governmental influences

Factors changing the economic implication of treatment of dental caries :-

I. The host ( teeth, saliva)

II. Micro flora

III. Substrate (diet)

Dental caries is a multifactorial disease in which there is an interplay of 3 principle factors.

Composition

Morphologic characteristics

Position

I. HOST FACTORS

Inorganic : 96%

Organic + water : 4%

Composition of tooth Enamel

Inorganic :65%

- Organic matter +water :35%

Composition of tooth Dentin

Inorganic : 45-50%

Organic +water : 50- 55%

Composition of tooth Cementum

Morphological characteristics of the tooth

Feature predisposed to the development of dental caries is presence of deep narrow occlusal fissure/ buccal and lingual pits

Tooth position

Which are malaligned, out of position, rotated or otherwise not normally situated, may be difficult to clean and tend to favor the accumulation of food and debris which subsequently lead to dental caries

Composition

PH

Quantity

Viscosity

Antibacterial factors

Saliva components in etiology

Age

Dental caries decreases as __ increases

Elders

Root caries are common in ___

Gingival recession

cemental exposure (improper brushing)

Low chance

Socio Econimic Status High:

High Chance

Socioeconomic Status Low:

Strep. Mutans

Lactobacilli

Actinomyces

What are the microfloras

stretococcus mutans

Microfloras

early carious lesions of enamel

Lactobacilli

Microfloras

dentinal caries

Actinomyces

Microfloras

root caries

Prerequisite for dental caries initiation

A single type of microbe is capable of inducing dental caries

Ability to produce acid  prerequisite for caries induction

Streptococcus strains are capable of inducing caries

Organisms vary greatly in their ability to induce caries

Role of microorganisms in dental caries

sterile mouth.

Dental caries does not occur in a ___ no mouth can ever be made sterile

metabolize sugar, acids

The conditions in the oral cavity are ideal for the growth of bacteria that ____ to ___.

37°C

The oral cavity is generally a warm place, at body temperature (___) encouraging the growth of bacteria.

Transmission of MS

Vertical transmission

Source is usually mother

Transmission may occur at birth, but MS reside in low numbers in reservoirs such as tonsils or dorsum of tongue

Birth, tonsils, dorsum of the tongue

Vertical transmission

Source is usually mother

Transmission may occur at ___, but MS reside in low numbers in reservoirs such as ____ or ____

soft, non mineralized, bacterial deposit which forms on a teeth that are not adequately cleaned

Complex metabolically interconned highly organized bacteria/ ecosystem

Important component of dental plaque is acquired pellicle  just prior or concomitantly with bacterial colonization and may facilitate plaque formation

Role of dental plaque

streptococci

 actinomycetes

 veillonella

Microbial in dental plaque

Strep. mutans

chief etiological agent of dental caries

Carbohydrate

Increase in ____ increase carious activity

retained on the surface of the teeth

Risk of caries is greater if the sugar is consumed in a form that will be ___

Consumed between meals

Risk of sugar increasing caries activity if it is ____

widely between individuals

Increasing caries activity varies ___

Rapidly dissapears

Upon withdrawal of the sugar rich foods the increased caries activity ___

refined sugar and maximum restriction on natural sugars dietary carbohydrates

Carious lesion may continue to appear desperate to avoidance of ___

High concentration sugar in solution and its prolonged retention on the tooth surface leads to increased caries activity

_____ in solution and its prolonged retention on the tooth surface leads to increased caries activity

Clearance time

____ of the sugar correlates closely with caries activity