At first, its mostly streptococci, then microbiota becomes more diverse
O2 decreases --> mostly anaerobic --> more fermentation
10
What is biofilm dispersion?
Show answer
biofilms can release bacteria to colonize new areas
the remaining plaque can eventually calcify into calculus (tartar).
11
3 stages of the caries process
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Acidogenic stage: Production of acid
Aciduric stage: Selection of bacteria that can survive in low pH
Proteolytic stage: Degradation of the organic matrix of teeth (after acids have demineralized inorganic matrix)
12
Where can fermentation take place
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GI and Oral cavaity
13
What is Specific Plaque Theory (60s-80s)
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Only pathogen bacteria are responsible for disease.
Emphasis on
- Streptococcus mutans (early colonizer)
- Lactobacillus (late colonizer, deep dentinal caries)
- Actinomyces (late colonizer, root caries)
14
What is the tooth Worm Theory?
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Sumerians in 5000 BC to the Egyptians, Greeks and Chinese up to the Middle Ages
• worm eating tooth away like apple
15
Which sugars are also highly cariogenic but do not build glucans like sucrose
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Glucose/dextrose
fructose
16
What condition did the Homo rhodesiensis specimen exhibit?
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extensive dental caries
17
What period is known for the earliest documented dental treatments?
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Neolithic period
18
Where was the earliest evidence of dental caries intervention found?
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Northern Italy
19
What theory did the Greek and Roman beliefs about health originate from?
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Hippocrates theory
20
What were the four humors/fluids believed to be within the body?
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• Phlegmatic: phlegm
• sanguine: blood
• melancholic: black bile
• choleric: yellow bile
21
What period saw an increase in sugar cane consumption leading to an increase in caries?
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11th to mid-18th century BC
22
What did Leeuwehoek discover using material scraped off his own teeth?
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Early discovery of microbes
23
What did Pierre Fauchard propose caused tooth decay?
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Tartaric acids derived from sugars and starches
24
What is the Chemoparasitic Theory?
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First to propose that microorganisms ferment carbohydrates to produce acids that demineralize tooth enamel
What is the primary acid produced by Streptococcus mutans?
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lactic acid
27
What is the significance of Streptococcus mutans in cariology research?
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model bacterium:
• Highly acidogenic
• Aciduric (survives in low pH environments)
• Produces extracellular glycans via glucosyltransferases (biofilm formation)
• Strongly associated with smooth surface caries
• Easily cultured in a laboratory
28
What was the primary focus of early microbiological research from the late 1800s to the mid 1900s?
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Pure monocultures of bacteria
29
What did Koch's postulates require to prove a bacteria causes a disease?
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▪ Association: Find the bacteria in all examples of ill patients
▪ Isolation: Isolate that bacteria in a pure culture
▪ Inoculation: Induce disease in a healthy host with that bacteria
▪ Reisolation: Reisolate that bacteria again from the induced patient
30
What significant improvements in technology allowed researchers to image the surfaces of stubborn bacterial conditions in the 1970s?
Show answer
Scanning Electron Microscopy
31
What type of communication do biofilm bacteria exhibit?
Show answer
Quorum sensing
32
What percentage of human bacterial infections are associated with biofilms?
Show answer
80%
33
Why do antibiotics become less effective once a biofilm matures on a heart valve?
Show answer
Because biofilms protect bacteria from antibiotics
34
Why are S. mutans models alone insufficient to explain disease?
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They dramatically underestimate the activity and resistance of biofilm-mediated disease
35
What does sucrose do to plaque architecture?
Show answer
Increases the number and activity of cariogenic bacteria
36
What is an acquired pellicle
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thin, bacteria-free conditioning film
Made of:
• salivary proteins
• glycoproteins
• lipids
• phospholipids
37
Which bacteria predominantly adhere to the acquired pellicle initially?
Show answer
Streptococci
38
What type of attachment do bacteria utilize appendages for?
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Permanent/Irreversible attachment
39
What happens to the biofilm during the maturation stage?
Show answer
It thickens and produces more acid
• more difficult to remove with brushing
• more likely to cause gingivitis/periodontal disease
• more likely to cause caries
40
What triggers the dispersion of mature biofilms?
Show answer
Nutrient limitation, environmental changes, or signaling molecules.
41
Stage of Biofilm formation times
Show answer
I. 2H
II. 8H
III. 14H
IV. 1-4 D
V. 5D
42
What type of carbohydrate are dentists most concerned about
Show answer
CARIOGENIC fermentable carbohydrates
fermentable for gut bacteria =/= fermentable for plaque bacteria
43
What was the primary theory regarding the cause of dental caries before the 1960s?
Show answer
Non specific plaque hypothesis
44
What is the non specific plaque hypothesis?
Show answer
Plaque is a random accumulation of bacteria.
Quantity determines severity
45
What leads to the selection of more acidogenic and aciduric bacteria in the plaque biofilm?
Show answer
Changes in environmental factors (sugar, pH, saliva, etc.)
46
What is the process by which dental caries develops?
Show answer
dysbiotic shift in the total plaque biofilm composition
47
What is the new model proposed for understanding dental caries?
Show answer
Ecological plaque hypothesis
48
What is the primary process involved in carbohydrate fermentation?
Show answer
anaerobic process
49
Which of the following can perform carbohydrate fermentation?
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bacteria, yeast, or fungi
50
What are the main products of bacterial carbohydrate fermentation?
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acid, alcohol, and gas
51
What does FODMAP stand for?
Show answer
Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols
52
What type of fermentation typically takes minutes?
Show answer
Oral fermentation
53
Which of the following is considered the most cariogenic?
Show answer
Sucrose (table sugar)
54
What does salivary amylase break cooked starches down into?
Show answer
Matose (glucose+glucose) or glucose
55
Which sugar is moderately cariogenic and fermented more slowly?
Show answer
Lactose
56
What is the primary reason sucrose is used as a model fermentable carbohydrate in caries research?
Show answer
It is rapidly fermented into acid and serves as substrate for extracellular glucan production
57
How does sucrose contribute to cariogenic plaque formation compared to other sugars?
Show answer
Produces more cariogenic plaque than glucose or fructose alone