Caries

Question 1

Bacteria in biofilms on the surface of the tooth produce ___________ from glycolysis of sugars.

Answer 1

Lactic acid

Question 2

Lactic acid drops ___ and the mineral matrix of the tooth dissolves.

Answer 2

pH

Question 3

Why is the initial demineralization only on the subsurface, leaving a thin layer of enamel overlying the lesion?

Answer 3

Pellicle proteins stabilize the surface

Question 4

Once ___________ occurs, biological repair is no longer possible.

Answer 4

Cavitation

Question 5

Why is remineralized tooth structure stronger than virgin enamel?

Answer 5

Incorporation of fluoride

Question 6

What is the most important property of caries-causing bacteria?

Answer 6

They continue to produce acid at low pH

Question 7

What species cause initial caries?

Answer 7

1. Strep mutans
2. Other strep (sobrinus, salivarius)
3. Veillonella
4. Actinomyces

Question 8

What species cause caries progression?

Answer 8

1. S. Mutans
2. Lactobacillus casei, rhamnosus, gasseri, fermentum
3. Bifidobacterium and scardovia

Question 9

What is the most common supragingival organism?

Answer 9

Streptococci

Question 10

What is the only nutrient source for S. Mutans?

Answer 10

Carbohydrates

Question 11

T/F: S. Mutans is good at surviving during feast and famine.

Answer 11

True

Question 12

What strep is very closely related to strep mutans?

Answer 12

S. Sobrinus

Question 13

T/F: S. Mitis is a caries causing bacteria.

Answer 13

False

Question 14

What is the earliest acquired oral bacteria?

Answer 14

S. Mitis

Question 15

What strep is found in healthy plaque and is a good initial colonizer of the pellicle?

Answer 15

S. Sanguinis

Question 16

T/F: S. sanguinis produces cannot produce lactic acid at low pH.

Answer 16

True

Question 17

What bacteria may be associated with root caries?

Answer 17

Actinomyces

Question 18

T/F: Actinomyces is anaerobic.

Answer 18

True

Question 19

T/F: Veillonella ferments carbohydrates to create lactic acid.

Answer 19

FALSE

Protects against acid by fermenting lactate

Question 20

At what point do lactobacilli play a role?

Answer 20

Established or deep lesions

Question 21

What is the initial process of attachment for caries development?

Answer 21

S. Sanguinis binds to pellicle -> s. Mutans binds to s. Sanguinis -> s. mutans makes extracellular matrix

Question 22

How does S. Mutans make extracellular matrix?

Answer 22

Uses glucosyltransferase (Gtf) to make ECM from sucrose

Question 23

What is the major component of the ECM?

Answer 23

Glucan

Question 24

T/F: S. Sanguinis does better than s. Mutans at low pH.

Answer 24

False

S. Mutans dominates at low pH

Question 25

What is the major difference between good and bad bacteria?

Answer 25

Good = grow and make acid at high pH but stop at low pH Bad = Grow and make acid best at low pH

Question 26

What is the short term effect of sugar consumption?

Answer 26

Drops the oral pH

Question 27

What is the long term effect of sugar consumption?

Answer 27

Selection for cariogenic bacteria over healthy bacteria

Question 28

What would be the targets of a caries vaccine?

Answer 28

Gtf and glucan binding proteins

Question 29

What are the two types of vaccines under investigation for caries?

Answer 29

Active immunity = mucosal vaccination; need adjuvants Passive immunity = antibodies grown in tobacco plants and cows milk

Question 30

What is replacement therapy?

Answer 30

Replace wild-type S. Mutans with strain that does not produce lactate

Question 31

What is a STAMP?

Answer 31

Antibody guided antimicrobial