Theories &Diagnosis of Dental caries

Theories &Diagnosis of Dental caries
Lecture ( 6 )
Dr.Baha, H. AL-Amiedi
Ph.D.Microbiology

NORMAL TOOTH


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 Rods








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 : filmentous microorganisms caused decomposition of the enamel and the dentin


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.


Bacterial caries susceptibility test(synder test):
Many attepts have been made to develop sutable
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 microflora of caries & whether these microflora of caries are capable of producing acid when incubated with sugar, usually glucose.
There have have been number of modifications of this test in 1965 Grainger introduced a swab for the buccal surface of teeth, the placing in semifluid synder type medium& incubating at 37 C for 96 hr
Test reading by color comparison to standard test.

Reading of synder modification test Diffusion acid
color change to from yellow top down one fourth
or less of tube, from top down +

color change to yellow, one half of tube ++
from top down

color change to yellow, three fourths of +++
tube , from top down

color change to yellow, entire tube ++++
No color change _
Interactions among dental plaque bacteria
The current approach to diagnose
The current approach to diagnose
dental caries
“Gross” Visual Examination
Mechanical Probing and X-ray

The current approach to treat
dental caries


Surgical repair

Fluoride treatment

Mechanical removal







The end