Operative

Question 1

Initial colonizing bacteria

Answer 1

gram positive, facultative -> actinomyces viscosus, strep sanguinis

Question 2

What material forms the hybrid layer?

Answer 2

silane

Question 3

What is the primary photo initiator in most composite resins? What wavelength does it absorb photons primarily?

Answer 3

camphoroquinone, 470 nm

Question 4

What is the initiator used in chemical or self-cure composites?

Answer 4

Benzoyl peroxide

Question 5

At what pH does demineralization of hydroxyapatite enamel occur?

Answer 5

5.5

Question 6

At what pH does the demineralization of dentin occur?

Answer 6

6.2

Question 7

At what pH does the demineralization of hydroxyfluoroapatite occur?

Answer 7

4.5

Question 8

What is the mechanism of action of CaOH?

Answer 8

induces dentin bridge formation within the dentin pulp complex

Question 9

What are the 2 main functions of primer?

Answer 9

1. infiltrate and remove water from enamel prisms, dentin tubules, and exposed collagen network
2. form the hybrid layer

Question 10

How is the hybrid layer formed?

Answer 10

ETCH removes smear layer, exposes collagen network, then PRIMER penetrates and allows adhesive resin to form micro tags

Question 11

The number and diameter of dentinal tubules ___ closer to the pulp.

Answer 11

increases

Question 12

The ___ phase decreases the strength of amalgam.

Answer 12

Gamma 2

Question 13

How do we avoid a decrease in strength of amalgam and why does that work?

Answer 13

Condensing, which brings excess mercury to the surface of the amalgam to be removed.

Question 14

What is a property unique to amalgam and has to do with marginal sealing?

Answer 14

Amalgam is the only restorative material that improves its marginal seal with age.

Question 15

What is the point of trituration of amalgam?

Answer 15

Remove the oxide coating and wet each particle of the alloy with mercury

Question 16

What are the optimal water levels of fluoride?

Answer 16

0.7-1.2 ppm (mg/L)

Question 17

Rank tooth colored restorations in order of decreasing fluoride release:

Answer 17

GI > RMGI > compomers > composite resin

Question 18

Fracture toughness is?

Answer 18

the material’s ability to resist propagation of a crack

Question 19

How can the setting time of ZOE be accelerated?

Answer 19

add water

Question 20

Amalgam contains what metals?

Answer 20

Mercury, silver, copper, tin

Question 21

Why is zinc added to amalgam? (4)

Answer 21

1. prevents oxidation of other metals in the alloy, (amalgam doesn’t darken)
2. enhances mechanical properties
3. reduces marginal fracture rate
4. prolongs the life

Question 22

True or false: overmixing amalgam reduces its strength.

Answer 22

FALSE

Question 23

What bacteria primarily cause root caries?

Answer 23

Actinomyces viscosus

Question 24

Which bacteria is associated with dental caries?

Answer 24

Strep mutans

Question 25

which phase of amalgam is the weakest?

Answer 25

gamma 2

Question 26

What is the half life of mercury in the human body?

Answer 26

55 days

Question 27

What is the dental hand instrument formula?

Answer 27

1- width of blade 2- if present, primary cutting angle 3- length of blade 4- blade angle

Question 28

How does amalgam set up?

Answer 28

mercury reacts with silver on or in the alloy particles

Question 29

What is eburnated dentin?

Answer 29

sclerotic dentin, appears dark from extrinsic staining, is firm, is seen in older patients

Question 30

The additional resin in RMGIs compared to conventional GIs causes what disadvantage?

Answer 30

increased thermal expansion

Question 31

The most common cause of fracture at the isthmus of a class II restoration is:

Answer 31

sharp axio-pulpal line angle

Question 32

What is the most important factor of a preparation that affects the pulpal response?

Answer 32

remaining dentinal thickness (RDT)

Question 33

What polishers are good for amalgam?

Answer 33

Prophy cup + tin oxide Abrasive-impregnated rubber points Sof-lex disks

Question 34

Over-condensing amalgam will lead to?

Answer 34

chipping and flaking during carving

Question 35

prolonged condensation of amalgam causes?

Answer 35

decreased strength

Question 36

Silicate cements are not good for ____ restorations because _____.

Answer 36

inter proximal, easily wear

Question 37

Minimum number of flutes a carbide bur needs to be considered "finishing"?

Answer 37

12

Question 38

Strongest phase of amalgam?

Answer 38

gamma 1

Question 39

Weakest phase of amalgam?

Answer 39

gamma 2

Question 40

High noble metals have approximately what % gold?

Answer 40

40%

Question 41

What primarily determines the character of teeth?

Answer 41

Texture of enamel