DrRai Tariq Masood Early Theories Worm Theory Humour Theory Parasitic Theory Vital Theory Chemical Theory Chemoparasitic Theory Proteolytic Theory Proteolysis Chelation Theory ID: 234444
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Slide1
Etiology of Dental Caries
Dr.Rai
Tariq
MasoodSlide2
Early Theories
Worm Theory
Humour
Theory
Parasitic Theory
Vital Theory
Chemical Theory
Chemo-parasitic Theory
Proteolytic
Theory
Proteolysis-
Chelation
TheorySlide3
Current Concepts of Caries Etiology
Keyes Circles
Caries is multi-factorial disease comprising of four factors
Susceptible Tooth Surface
Micro-organism
Diet (Sucrose)
Appropriate time
Each one of them is of equal importance in
aetiology
of cariesSlide4
Classification Based on Morphology
Occlusal
Caries ( Pit & Fissure Caries)
Smooth Surface Caries
Buccal
& Lingual Caries
Proximal CariesSlide5Slide6
Classification Based on Severity & Progression
Rampant Caries
Early Childhood Caries ( Baby Bottle Tooth Decay)
Radiation CariesSlide7
Classification Based on Part of Tooth Involved
Enamel Caries
Dentinal Caries
Cemental
CariesSlide8
Classification Based on Activity
Primary Caries
Secondary Caries
Residual Caries
Arrested CariesSlide9Slide10
Clinical Manifestations of Caries Process
1-
Early Changes
First time demineralization of enamel when PH falls below 5.2 – 5.5
Demineralization can not be detected clinicallySlide11
2- White Spot Lesion
First visible clinical presentation
Caused by sub-surface enamel demineralization
Surface is intact
It may or may not progress to frank
cavitationSlide12Slide13
3- Hidden or Occult Caries
Calcium and Phosphate moves from subsurface to the surface.
Calcium and Phosphate along with fluoride from saliva precipitate on effected surface enamel.
It will occlude the pores that limits demineralization of surface enamel.
Hence intact surface enamel and caries in subsurface level.
Not clinically visible.Slide14
4- Frank
Cavitation
Sub-surface carious lesion increases in dimensions.
Collapse of surface layer
Cavitation
More plaque accumulation so rapid tooth destruction.
It takes 18 (+- 6 months) to progress from white lesion to
cavitation
.Slide15
5- Arrested Caries
Carious lesion can become arrested at any stage.
If the causal factors are changed or protective factors are increased.
Example :Proximal Carious lesion and if adjacent tooth is lost then it becomes self cleansing.Slide16
Micro-Biology of Dental Caries
Streptococcus
Mutans
Ability to stick to tooth surfaces
Ability to produce lactic acid
Resist the
acidogenic
environment
Produce intracellular polysaccharide
Streptococcus
Sobrinus
LactobacillusSlide17
Formation o
f Plaque
Adherence of bacteria to pellicle or enamel surface.
Adhesion between bacteria by polysaccharide chains
Subsequent growth of bacteriaSlide18
Risk Factors/Protective Factors
Total oral Bacterial population
Tooth Morphology
Salivary secretion rate
Intake of carbohydrates
Oral Hygiene Habits
Use of FluoridesSlide19
Role of Saliva in Caries
Also called
Liquid Enamel
because of high mineral content
Cleansing Action
Buffering Capacity
Antibacterial Action by
Lysozyme,Lactoperoxidase,hemoprotein
enzyme (Prevents bacterial colonization)
Saturated with Calcium and Phosphate
Most prominent antibody in saliva IGA.
Proteins like
statherin
protects
hydroxyapetite
crystals.Slide20
Flow rate:
Role of saliva, with respect to caries, is in the removal of bacterial and debris. Average un-stimulated flow rate is 0.3 ml/minute and amount prior to swallowing 0.9-1.2 ml
Quantity
: Normal is 700-800 ml/day. Less leads to rampant caries as seen in
Xerostomia
.
Viscosity:
Thick saliva associated with high caries but not confirmed.
pH:
Depends on bicarbonate
content.Saliva
may be slightly acidic as it is secreted at
unstimulated
flow rates but may reach PH of 7.8 at high flow rates.Slide21
Buffering Action
Bicarbonates are most important buffers
It reacts with acid and release weak carbonic acid.
Carbonic acid is rapidly decomposed into water and carbon dioxide.
So acid is completely removed.
When there is excess sucrose
intake,intense
acid production will breakdown the buffers.Slide22
Thank you