Caries

Question 1

What is the only organism that can dissolve enamel?

Answer 1

S. mutans

Question 2

____ occurs close to the gingiva due to the curvature of the teeth and stagnation areas and free-cleansing.

Answer 2

White spot lesion

Question 3

Once cavitation starts, _____ come in because it’s a little more acidic.

Answer 3

lactobacilli

Question 4

Dentinal tubules go _____

Answer 4

apically

Question 5

Caries in dentin expands _____

Answer 5

laterally

Question 6

_____ does not cause damage, only initiates the lesion.

Answer 6

S. mutans

Question 7

What are the four things needed for caries?

Answer 7

susceptible tooth or oral environment
cariogenic bacteria
time
cariogenic diet

Question 8

True or False? Removal of ONE of the four things for caries and caries does not take place.

Answer 8

True

Question 9

List the age groups in order of most new lesions per year to least new lesion per year.

Answer 9

Teens
4 to 6
Elders
Young adults

Question 10

What are the 4 conclusions of the Vipeholm Study?

Answer 10

• retentive sugar is more cariogenic than non-retentive
• sugar consumption between meals is more cariogenic than at mealtime only
• the frequency of sugar intake/day is more important in caries than the total amount of sugar consumed/day
• sugar restriction (i.e. no between meal sweet snacks) can inhibit new caries formation even in individuals with a history of high dental caries

Question 11

Caries active subjects have a ____ Stephan curve than caries free.

Answer 11

deeper

Question 12

Subjects with salivary stimulation by chewing on parafin had a _____ Stephan curve.

Answer 12

higher

Question 13

Arginine peptides and urea cause pH to ____

Answer 13

rise

Question 14

_____ species in plaque change the pH back to resting pH

Answer 14

Alkali-forming

Question 15

True or False? Whether there is a lot of sugar or little, the pH comes out almost the same.

Answer 15

True

Question 16

When S. mutans-like bacteria were examined closely, they differed serologically, genetically, and enzymatically but all were highly cariogenic in animals. This family was called _____

Answer 16

mutans streptococci (MS)

Question 17

What are the two mutans streptococci species that affect human teeth?

Answer 17

Streptococci mutans c,e,f

Streptococci sobrinus d,g

Question 18

MS usually only colonizes ____ oral surfaces.

Answer 18

hard

Question 19

True or False? MS occupies the deep regions of the plaque adjacent to the tooth.

Answer 19

True

Question 20

_____ causes expansion of MS in plaque due to polysaccharide formation.

Answer 20

Dietary sucrose

Question 21

The origin of MS has been determined by genetic techniques to be the _____

Answer 21

mother

Question 22

Mother’s MS is colonized in the child during the first ____ months

Answer 22

31

Question 23

After age 3, acquisition of _____ is unlikely.

Answer 23

non-indigenous MS

Question 24

_____ transmission of MS occurs readily

Answer 24

Intraoral

Question 25

MS preferred habitat is ____ where the environment is slightly acidic

Answer 25

pits and fissures

Question 26

An environmental pH of ____ stimulates MS growth

Answer 26

6

Question 27

_____ does not thrive in sub-gingival ecosystems

Answer 27

MS

Question 28

When MS exceeds ____ per ml of saliva, this indicates the individual is at risk for dental caries.

Answer 28

10^5

Question 29

Quorum sensing molecules of MS upregulates _____ production

Answer 29

mutacin

Question 30

___ is an anti-strep bacteriocin

Answer 30

mutacin

Question 31

MS acid and mutacin destroys ____

Answer 31

S. sanguinis

Question 32

_____ inhibits quorem sensing molecules which upregulate mutacin

Answer 32

Challisin

Question 33

____ is a peptide from S. gordonii

Answer 33

Challisin

Question 34

S. sanguinis kills MS with its ______

Answer 34

hydrogen peroxide

Question 35

MS ____ when sucrose is present

Answer 35

expands

Question 36

Lactobacilli prefer a pH of ____

Answer 36

5

Question 37

True or False? MS do not tolerate the low pH of the dentinal lesion.

Answer 37

True

Question 38

What three lactobacilli dominate and cause dentinal carious lesions?

Answer 38

L. casei, L. rhamnosus, L. fermentum

Question 39

Most LB are ____ and _____ producing mainly lactic acid as a by-product

Answer 39

facultative; saccharolytic

Question 40

True or False? LB usually do not colonize subgingivlly

Answer 40

True

Question 41

True or False? The tongue is the main soft tissue habitat

Answer 41

True

Question 42

True or False? LB is as very susceptible to fluoride as MS, or to the antimicrobial agents, chlorhexidine and xylitol

Answer 42

False. LB is not as susceptible to fluoride as MS, or antimicrobial agents, chlorhexidine and xylitol

Question 43

____ is a polymer of glucose molecules

Answer 43

glucan

Question 44

_____ is a polymer of glucose molecules on MS

Answer 44

mutan

Question 45

MS ECP is a _____ linked glucan. It is called a mutan and only exists in nature on MS

Answer 45

alpha 1 to 3

Question 46

What are the properties of water mutan?

Answer 46

water insoluble

not metabolized by non-MS oral bacteria

Question 47

What does mutan do?

Answer 47

1. mutan protects MS from antagonistic factors
2. mutan helps focus acid from MS on the tooth surface
3. mutan ehnances proliferation of MS in plaque and increases plaque volume (this hinders penetration by salivary buffers
4. mutan does not directly harm the tooth