Carious Lesions Flashcards
Carious lesions
A multifactorial process of demineralization and remineralization and are often reversible.
How does a carious lesion form?
Undisturbed dental biofilm (plaque) is left undisturbed on a tooth surface
Dental caries are a symptom of what?
Bacterial infection
What is dental plaque?
A biofilm that is natural and physiological process.
Active community of microorganisms that work together
What are the bacterial factors of dental plaque that cause caries?
Streptococcus mutans
Streptococcus sobrinus
Lactobacilli
Non cariogenic bacteria can become cariogenic under the right circumstances. T or F
True
What do cariogenic bacteria do or produce that cause demineralization?
Metabolize sucrose into LACTIC ACID
What components does the rate of caries formation depend on? (7)
Microbial Status Saliva Quantity Saliva Quality Carbohydrates Oral Hygiene Tooth surface Host defense
When classifying a carious surface what terms are used?
Surface: Smooth or Pit and Fissure
Cavitated or noncavitated
Active or inactive
What are the steps of dental biofilm development?
- Pellicle Foramtion (min to hrs)
- Attachment of single bacterial cell (0-24 hr)
- Growth of attached bacteria, colonization (4-24 hr)
- Microbial succesion and coadhesion - increased species diversity.
- Climax community > or = 1 week
What is the Specific Plaque Hypothesis?
Plaque is a problem but it is not the plaque itself but the SPECIFIC concentration of CARIOGENIC BACTERIA.
What are treatments for specific plaque hypothesis?
Plaque removal
Diet modifications
Bacterial Testing
Antimicrobials
Why is saliva good? (4)
Inhibits some bacterial growth (enzymes)
Dilute and eliminate bacteria
Buffer to bacterial acids
Reparative (calcium and phosphorus for remineralization)
Microbial Succesion
The microflora shifts from streptococcus dominated plaque to a plaque dominated by actinomyces.
Shift in microbial communites is known as microbial succession.
Microbial Colonization
initally bacteria are adhered to tooth surface via van der Waal’s attractive forces.
Streptococci have a low affinity of bonding - consist of only 2 % of microflora.
High risk caries patient
A patient with an abnormally high level of streptococci levels in the patients dental plaque (microflora)
What are the functions of a pellicle?
Protects tooth from food acids and plaque acids
Provides matrix for enamel remineralization
Lubrication - easier for teeth to more against one another.
FORMS THS MAJOR SURFACE FOR BACTERIAL COLONIZATION.
What are the major constituents of the pellicle?
Salivary glyoproteins
Phosphoproteins
Lipids
Gingival crevicular fluid
What is xylitol?
Natural sweetner that cariogenic bacteria can not metabolize
Why does tooth eruption create a novel surface for bacterial colonization?
The epithelium of the mouth sheds often. Tooth surface is non shedding and allows the bacterial to remain.
Streptococci mutans and Streptococcus sanguine generally only appear after tooth eruption. T or F
True
What is the window of infectivity?
The age at which some bacteria optimally infect. 19 - 31 weeks.
Why is microflora good (residential flora)?
Saturate microbial attachment sites
Effective competition for nutrients
Create conditions unfavorable to growth
Produce inhibitory factors
If the normal flora is broken down what could happen?
overgrowth of exogenously acquired and potentially pathogenic organisms.
