Lecture 2

Question 1

Critical pH for enamel (hydroxyapitite)?

Answer 1

5.5

Question 2

Critical pH for dentin?

Answer 2

6.2

Question 3

Critical pH for enamel(hydroxyfluorapitite)?

Answer 3

4.5

Question 4

When does filamentous bacteria begin to invade cocci microcolonies in the biofilm?

Answer 4

at 1 week

Question 5

Plaque near gingival sulcus has more cocci or filamentous bacteria?

Answer 5

Filamentous

Question 6

When is biofilm comprised primarily of filamentous bacteria?

Answer 6

at 3 weeks

Question 7

What are the 3 predominant species in the mucosa habitat?

Answer 7

S. mitis, S. sanguis, S. salivarius

Question 8

What are the 3 predominant species in the tongue habitat?

Answer 8

S. mutans, S. sanguis, S. salivarius

Question 9

What is the predominant(non-carious) species on the teeth?

Answer 9

S. sanguis

Question 10

What is the pH of the mucosa habitat?

Answer 10

~ 7.0

Question 11

What is the pH of the tongue habitat?

Answer 11

~ 7.0

Question 12

What is the pH of the tooth habitat?

Answer 12

~ 5.5

Question 13

What are the four predominant species of the gingival crevice habitat?

Answer 13

Fusobacterium, Spirochaeta, Actnomyces,

Veillonella

Question 14

What is the predominant species in enamel caries?

Answer 14

S. mutans

Question 15

What are the two predominant species in dentin caries?

Answer 15

S. mutans, lactobacillus

Question 16

What is the predominant species in root caries?

Answer 16

Actinomyces

Question 17

What is the scientific name for dry mouth?

Answer 17

xerostomia

Question 18

The buffering capacity of saliva is

determined primarily by the concentration of what ion?

Answer 18

bicarbonate