Classification of Dental caries

Dental caries can be classified with respect

to the site of the lesion and

diagrammatically in of lesion as

1- Bit and fissuer

2- Smooth Surface

3- Root surface

4- Recureent caries

Bacterial associated with caries

type caries type microorganisms isolate

pit and fissure S . mutans , S.sanguis

S .mitis, lactobacilli

Actinomyces

Smooth surface S. mutans

Dental caries lactobacilli

S. mutans

A. naeslundii

Filumentous Rods

A viscosus

Root caries A. viscosus .

A naeslundii,

A salivarius

S mutans, S sanguis

Filamentous Rodes

Aetiology

The main factors involved in dental caries are

the tooth, saliva, supragingival plaque, the diet

(especially sucrose intake) and the time

necessary for caries development These

complex factors can interact in numerous

different ways, but certain pat-terns of

interrelationships are more likely than others

to result in the initiation and progression of

carious lesions or healing of an early white

spot lesion

Major Factors

1-Role of plaque(bacteria)

2-Role of saliva

3-Role of carbohydrate

4-Role of time

Aetiology of Dental Caries

MAJOR FACTORS

1. Role of plaque (bacteria)

Normal flora of the oral cavity contains

abundance of bacteria which derive there

energy by the chemical process of

fermentation

Mainly the bacteria are Streptococcus

Mutans,and streptococcus sobrinus

collectively known mutans streptococci(MS)

Demineralization of the tooth surface

caused by bacteria

MINOR FACTORS

1-Enamel composition

2-Morphology of the tooth

3- Position of the tooth

4-Diet

5-Immunity

Theories of etiology of caries

1-Early Theories :

A-Worms tooth aches caries caused by worm

B-Humors : unbalance between the humors : ( blood , black bile , yellow bile )

2-Vital Theory : origination of dental caries with in tooth it self extensive penetration into the dentin & into pulp

3-Chemical Theory : chemical agents responsible for caries

4-Parasitic or septic Theory : filmentousmicroorganisms caused decomposition of the enamel and the dentin

Theories of etiology of caries

5-Chemo - parasitic Theory (Miller 1890) : caries is caused by acids produced by oral cavity microorganisms of the mouth miller 1890 concluded that the process was mediated by microorganisms produced acids and digestion proteins .

6-Proteolytic Theory(Gottlib 1944) : it has been proposed that the organic matrix or protein elements of enamel are the initial pathway of invasion by oral cavity microorganisms

7-Proteolysis – chelation Theory : this theory considers dental caries to be bacterial destruction of teeth where the initial attack essentially on organic component of enamel and the end products of proteolysis acts as a chelating- agent.

ASSESSMEBT TOOLSStepwise progression toward diagnoses&

treatment planning depending on through

assessment of following:

1-Patient History

2-Clinical Examination

3-Nutrtional Analysis

4-Salivery Analysis

5-Radiografic Assessment

Caries activity:

*Refer to the increment of active lesion(new

& recurrent lesions)over a stated period of

time

*caries activity is measure of speed of

progression of carious lesion

.

Caries susceptibility

*Refers to the inherent tendency of host

&target tissue, the tooth to be affected by

the carious process (study of genes)

Requirement of caries activity test

1-test should be simple

2-test should be reproducible & valid

3-test should be good correlation between the caries activity scores& actual caries development.

4-Result should be obtain rapidly within hours or few days

5-should have measurement of mechanisms involved in caries process

6-should be inexpensive , non-invasive & applicable to clinical setting.

Caries activity testes

1-synder test

2-reductase test

3-enumael solubility test

4-saliva flow test

5-saliva buffer capacity

6-lactobacillus colony count test

7-streptococcus screening test

8-fosdisk calcium dissolution test

9-ora test-

Bacterial caries susceptibility test(snyder test):

Many attempts have been made to develop suitable

diagnosis test for the determination of caries susceptibility of an individual. most of these tests have been based on differences in type of bacteria

present in the micro flora of caries & whether these micro flora of caries are capable of producing acid when incubated with sugar, usually glucose.

There have been number of modifications of this test in 1965 Grainger introduced a swab for the buccal surface of teeth, the placing in semifluid snyder medium& incubating at 37 C for 96 hr

Table illustrated snyder test