dental caries theories & diagnosis

Dental caries
Dr.Baha, H. AL-Amiedi
Ph.D.Microbiology
Dental caries:
can be thought of as a chronic infection of enamel or dentine in which the microbial agents are members of the normal commensal flora. Lesions result from the demineralization of enamel or dentine by acids produced by plaque micro-organisms as they metabolize dietary carbohydrates. Once the surface layer of enamel has been lost, the infection invariably progresses via dentine, with the pulp becoming firstly inflamed and later necrotic 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 Factor involved in dental caries.
(Dental plaque(Microorganism 1-
-2-Saliva
--Diet3-
Minor factor involved in dental caries-
1-Morphilogy of the tooth
2-position of the tooth
3-Enemal composition
-lmmue
Theories of etiology of caries
-Early Theories 1-
A-Worms tooth aches caries caused by worm
B-Humors : unbalance between the humors : ( blood , black bile , yellow bile )
2-2-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 3-
4-4-Parasitic or septic Theory : filmentous microorganisms caused decomposition of the enamel and the dentin nity
Caries Activity test
Thers are different caries activity tests:
1-lactobacillus colony test
2-synder test
3-swab test
reductase tes
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

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 ++++

The current approach to diagnose

The current approach to diagnose
dental caries
1-Naked eyes
2-X-ray
3-Mechanical probing