Definition:*

Caries calcified tissues of the teeth are modified and dissolved. By mainly Streptococcus mutans.

*Dental caries stages

*Demineralization And Remineralization

demineralization of enamel layer by microbial acids. (Reversible lesion)

Enamel starts to break down. (Irreversible lesion).

reach the tooth's pulp . ,reaches into the dentin where it can spread and

undermine the enamel.

1st stage (white (spots

2nd stage (Enamel decay(

4th stage (Pulp (involvement

3rd stage (Dentin decay(

Caries sites

Pit-and-fissure caries Smooth-surface caries .Root caries

RemineralizationRemineralizationLow pH

Salivary [Ca2+]Salivary [PO4

3-]Salivary [F-] DemineralizationDemineralization

Main Factors Involved In Dental Caries *

Teeth: the microbe challenges a susceptible surface on some areas of the tooth to attack than

other that related to many factor position and morphology of teeth.

: MicroorganismS mutans considered the caries initiator

: Dietmost cariogenic sugar is sucrose

Acidogenic bacteria

S viridanceas S .mutans.Lactobacillus sp

Proteolytic bacteria

.Actinomyces sp

.Colistridia sp

.Pseudomonas sp

Chromogenicbacteria

.Asprigillus sp

A b i l it y t o

a d he r e

t o t h e

t o o th

s u r fa c e

c o l on i z ati o n

) .)

P r o du c ti o n o f

g l u ca n s

a n do t h e

r p o l ys a c ch a r i d e s

t op l a q

u ea c c um u l a

ti o n .

P r o du c ti o n o f

a c i d s t o

P r o du c ti o n o fa c i d s

T o l e r a t e t h e l o w p H

v a l ue s .

Adherence factors (adhesins as pili(. Invasive factors e.g TB as the organism produces disease by invasion

of tissues. Ability to survive intracellularly as Neisseria sp. Toxic production as Dephtheria, the organism multiplies locally in

the throat but releases strong toxin diffuses to the blood._______________________________________________________

____________________________________________________

Important bacteria in caries

Streptococcus mutans.

Lactobacillisp

Actinomycessp.

(1) Extrusion of H+

(2) Malolactic fermentation

(3) Alternation of cell (4) Production of

ammonia

metabolize a variety of sugars,resulting in the production of a number of weak acids.

Initiators of smooth surface caries.

energy source plaque accumulation.

There is an outer fibrillar layer its function include : - Attachment to salivary pellicle. -Adhere to colonizing streptococci.

• The role of saliva in caries

The role of saliva in caries

Formation of acquired enamel

pellicle.

Washing effect of saliva.

Buffering effect of saliva.

Salivary antibodies.

Antibacterial substances.

DONE BE:

Ghadeer Hassan