Midterm 1: Cariology II Approximal Caries

Question 1

Where are approximal caries?

Answer 1

between teeth
enamel - enamel contact

Question 1

Class I caries are best prevented by what?

Answer 1

Fissure sealants

Question 2

Posterior approximal caries begin ____________ to contact area.

Answer 2

gingival

Question 3

Is there plaque retention between the posterior teeth?

Answer 3

YES

Question 4

Demineralization can be inhibited by _________.

Answer 4

fluoride

Question 5

How do posterior approximal caries form?

Answer 5

1. undisturbed plaque on smooth surface
2. plaque fed by carbohydrates
3. mineral loss at center of lesion

Question 6

What forms on the clean tooth surface to get caries?

Answer 6

pellicle
biofilm

Question 7

There is a state of equilibrium between _______________ and the oral environment/plaque.

Answer 7

Hydroxyapatite
Ca10(PO4)6(OH)2 —> Ca2+ + PO43-

Question 8

What is the critical pH for dentin?

Answer 8

6.2

Question 8

What causes the pH to decrease?

Answer 8

sugar
increases [H+]
sugar increase H+ level which pulls the phosphate out of the tooth

Question 9

What does bicarbonate do in saliva?

Answer 9

Bind with H+ to leave the equilibrium balance of calcium and phosphate untouched

Question 10

Bicarbonate in saliva serves as a ________.

Answer 10

Buffer
distractor

Question 10

What is saliva for and what does it provide for the mouth?

Answer 10

Natural rinsing (clearing bacteria/carbohydrates)
Bicarbonate (buffering capacity)
Calcium and phosphate
Fluoride

Question 11

What is a Stephan Curve?

Answer 11

Shows the balance of remineralization/demineralization throughout time

Question 12

What is the critical pH for enamel?

Answer 12

5.5

Question 13

For a _____ mouth, it takes longer for pH to return to neutral

Answer 13

dry

Question 14

What is the benefit of remineralization into fluorapatite?

Answer 14

fluroapatite has a critical pH of 4.5
better able to resist acid demineralization compared to hydroxyapatite

Question 15

With fluoride, the critical pH is now 4.5, which means what?

Answer 15

It takes a stronger acid challenge to start demineralization

Question 16

What are some characteristics of remineralization?

Answer 16

remineralization is a surface phernomenon
outer layer of enamel will remineralize
deeper enamel/affected dentin will not re-mineralize
will become shiner
radiolucency remains

Question 17

Posterior approximal caries have little ________ evidence and no __________ evidence.

Answer 17

visual
tactile

Question 18

How are posterior approximal caries diagnosed?

Answer 18

With X-rays

Question 18

What are approximal caries (E2)?

Answer 18

acids begin to affect underlying dentin
loss of mineral subjacent to demineralized enamel
some discoloration from stains
NO spread of demineralization along DEJ

Question 19

What are the categories of approximal caries?

Answer 19

E1
E2
D1
D2
D3

Question 19

What are approximal caries (E1)?

Answer 19

Superficial deminirelization of enamel
No changes in dentin

Question 20

What are approximal caries (D1)?

Answer 20

Cavitation of enamel destruction of outer dentin SUBSTANTIAL staining in dentin enamel will begin to break down spread in oval shape stain all the way to the pulp even if the damage is to the dentin only

Question 21

What are approximal caries (D2)?

Answer 21

Circumferential and axial destruction of dentin possible pulp involvement chalkiness shadowing of occlusal unsupported enamel broken away revealing dentin demineralization extending into middle third of dentin

Question 22

What are approximal caries (D3)?

Answer 22

Infection of pulp tissue circumferential destruction of dentin and undermining of enamel is extensive making repair with filling is UNRELIABLE

Question 23

What is the progression of caries?

Answer 23

1. enamel demineralization 2. dentin demineralization 3. enamel cavitation 4. dentin cavitation

Question 24

What are the pros and cons of panoramic radiographic diagnosis?

Answer 24

big picture NOT SENSITIVE ENOUGH for approximal caries if approximal caries are visible, TOO ADVANCED

Question 25

What are the pros and cons of periapical radiographic diagnosis?

Answer 25

angle of x-ray beam is usually to low/high to highlight horizontal oval lesion

Question 26

What should be used for radiographic diagnosis?

Answer 26

BITEWINGS

Question 27

Why are bitewings used to diagnose approximal caries?

Answer 27

designed to show approximal lesions show bone level

Question 28

How to prevent approximal caries?

Answer 28

Reduce fermentable carbohydrates Ex. sucrose, glucose, fructose, lactose tooth brushing flossing fluoride

Question 29

What is the worst fermentable carbohydrate?

Answer 29

sucrose

Question 30

Why is sucrose so bad?

Answer 30

The oxygen that binds glucose and fructorse Step mutans can use energy in that bond to link flucose with insoluble polymer: glucan this linkage causes strep mutans to bind to tooth structure quickly and strong

Question 31

What is surgical treatment for approximal caries?

Answer 31

remove defective tooth structure that is surrounded by solid tooth structure access through marginal ridge SIGNIFICAN weakening of tooth structure

Question 32

Posterior approximal lesions require access through which sound tooth structure?

Answer 32

marginal ridge

Question 33

__________ defects are easier to detect than _________ defects. (enamel or dentin?)

Answer 33

enamel dentin

Question 34

Proper flossing and fluoride application are effective in preventing lesions unless they are __________.

Answer 34

cavitated