Final

Question 1

Color category of the dentinal body

Answer 1

Hue

Question 2

Color saturation of the dentinal body

Answer 2

Chroma

Question 3

The degree of whiteness of enamel

Answer 3

Value

Question 4

White spots of different types and shapes

Answer 4

Intensives

Question 5

Blue or gray transparent effects found in enamel

Answer 5

Opalescence

Question 6

Do teeth become lighter or darker when dehydrated?

Answer 6

Lighter

Question 7

How long does it take for baseline shade to return after teeth have been dehydrated?

Answer 7

30 minutes

Question 8

What could be the controlling factor in the overall acceptance of a restoration by the patient

Answer 8

Color

Question 9

What features does dentin provide?

Answer 9

Color (primarily), opacity, lobes, and fluorescence

Question 10

What features does enamel provide?

Answer 10

Modification to dentin color, shape, and surface texture

Question 11

The higher the opacity of the material, the ___ it will mask the underlying color

Answer 11

More

More opaque - more it will mask oral cavity darkness - more it will reflect light - Hollywood smile

Question 12

The thinner the material, the less ___ it becomes

Answer 12

Opaque

Question 13

The lingual shelf is a thin layer of ___ ___ ___

Answer 13

Semi translucent enamel

Question 14

The dentin layer is the most ___ layer

Answer 14

Opaque

Question 15

What effect is seen at the incisal third?

Answer 15

Translucent effect

Question 16

Optical properties of some resin composites are affected with ___ and ___ ___

Answer 16

Time and water uptake

Question 17

The interaction between ___ and ___ gives the color of the tooth

Answer 17

Enamel and dentin

Question 18

The perceived tooth color is a combination of complex optical phenomena that occurs when…

Answer 18

Light hits the tooth

Question 19

The higher the ____, the brighter the color

Answer 19

Value

Question 20

What is the ideal height:width ratio (%) for centrals

Answer 20

80%

Question 21

How do composite materials bond to enamel?

Answer 21

Micromechanical retention through resin micro-tags (resin that fills the micro-porosities created by the acid etch and then polymerized)

Question 22

Does enamel require macro-mechanical retention?

Answer 22

No

Question 23

Name the % makeup of enamel

Answer 23

88% mineral, 10% water, 2% organic

Question 24

Name the % makeup of dentin

Answer 24

50% mineral, 25% water, 25% organic

Question 25

What does etching do? (3)

Answer 25

Dissolves hydroxyapatite, removes smear layer, increases total surface energy

Question 26

What do we etch with?

Answer 26

37% phosphoric acid

Question 27

Does acid etching increase bond strength in dentin

Answer 27

No.

Question 28

How long do you etch on a permanent tooth? A primary? What might cause the difference?

Answer 28

15 seconds for permanent 60-120 seconds for primary The primary enamel is amorphous and does not easily form the deep resin tags seen in permanent teeth

Question 29

How long do you rinse after etching?

Answer 29

10 seconds (longer if using gel etchant)

Question 30

What is the primary retentive feature when restoring with composite?

Answer 30

Bevels

Question 31

What is the point of a bevel?

Answer 31

Increases the enamel surface area to provide a better marginal seal and reduce marginal stains. Also increased esthetics to to more gradual transition between tooth and restoration

Question 32

Procedure of bonding to enamel

Answer 32

1. Select shade and dam 2. Place bevel and remove unsupported enamel 3. Etch 4. Rinse/Dry 5. Bonding resin (no scrubbing) 6. Composite

Question 33

What must happen if the etched enamel is contaminated

Answer 33

Must re-etch. Saliva and sulcular fluid decrease bond strengths

Question 34

What does dentin adhesion primarily rely on?

Answer 34

The penetration of adhesive monomers into the network of collagen fibers left exposed by acid etching (micromechanical retention)

Question 35

Procedure for bonding dentin

Answer 35

1. Etch (15 s) 2. Rinse/Dry 3. Place bonding resin (must scrub, unlike enamel) 4. Composite

Question 36

Dentin has ___ tensile strength and ___ modulus of elasticity than enamel

Answer 36

Higher | Lower

Question 37

______ dentin is more mineralized than _____ dentin

Answer 37

Peritubular | Intertubular

Question 38

What is the smear layer?

Answer 38

Adherent layer of tooth debris, saliva, and bacteria that covers surface and plugs tubules to reduce dentin permeability. It limits bond strength

Question 39

What happens when you dessicate dentin?

Answer 39

Collagen fibrils collapse which decreases bond strength by 50%

Question 40

What is the goal of all dentin bonding systems

Answer 40

Allow the bonding agent to penetrate the intertubular dentin, forming the hybrid layer (resin-dentin-interdiffusion zone)

Question 41

Explain a three-step etch system

Answer 41

1. Strong acid (37% phosphoric) for 20 seconds (enamel) and 15 seconds (dentin) - then rinse 2. Primer - scrubbed onto dentin 3. Resin adhesive (dried and polymerized with light)

Question 42

Why is priming necessary?

Answer 42

To maintain an expanded collagen network while removing residual water to allow for the infiltration of the hydrophobic adhesive monomer

Question 43

Explain a two-step etch system

Answer 43

1. Primer and bonding agent combined into one bottle 2. Acid etch remains separate We use OptiBond Solo Plus

Question 44

What is the procedure when using Optibond 2-step etch system

Answer 44

1. Rub bonding agent for 15 seconds 2. Gently blow air to thin 3. Rub bonding agent again for 15 seconds 4. Gently blow air again to thin 5. Light cure for 20 seconds

Question 45

Why do you rub the bonding agent?

Answer 45

Improves penetration and produces a thicker hybrid layer

Question 46

What does the air inhibited layer consist of?

Answer 46

Mainly uncured monomers

Question 47

____ etch removes the smear layer and causes more post-op sensitivity while ___ etch does not.

Answer 47

Total Self

Question 48

What is the role of primer

Answer 48

Increase surface tension of dentin