Test 2 Review

Question 1

what is the benefit of delayed cementation of fiber posts?

Answer 1

results in higher retentive strengths in comparison to immediate cementation and the best results were obtained when the luting agent was brought into the post space with lentigo spirals or specific syringes

Question 2

___ thickness influences the pullout strength of fiber-reinforced posts. The highest bond strength values are obtained when ___

Answer 2

• Resin cement fill
• the cement layer oversized the post spaces but not larger than 0.3mm

Question 3

When is the use of core build-up materials as post luting cements recommended?

Answer 3

Only one scenario: Don’t want to remove dentin to make room for a larger post. You can use the core build-up materials to cement the post in these cases. In other words, if you have a large gap, you can use the build-up materials to cement the post.

Question 4

What are 4 factors for the long term success of post endodontic restorations?

Answer 4

• occlusion
• preservation of tooth tissue
• presence of a ferrule effect
• adhesion

Question 5

Evidence shows that ___ posts are superior to metal posts or tooth-colored posts, like zirconia dowels.

Answer 5

fiber

Question 6

T or F:

Posts should be used to reinforce the tooth

Answer 6

false

they are used to retain restoration and not reinforce the tooth.

Question 7

___ and ___ forces influence the prognosis of restorations on endodontically treated teeth.

Answer 7

Functional and parafunctional

Question 8

Nonaxial forces are a risk for ___

Answer 8

fatigue fracture of teeth, cement, and restorative material.

Question 9

what are fundamental components of a complete laboratory prescription?

Answer 9

1. patient name
2. patient MRN number
3. date of prescription
4. due date of indirect restoration
5. school of dentistry name and contact info
6. tooth or teeth numbers
7. desired materials for indirect restoration
8. design info for indirect restoration (if indicated) – margin design, special instructions for material placement, pontic design if FPD
9. other special instructions
10. shade info if indicated
11. photographs if indicated (no cell phone pictures)
12. due date
13. attending signature
14. attending license number

Question 10

what are the 3 considerations/parameters/stipulations of tooth preparations, and what is the goal of the dentist with respect to these parameters?

Answer 10

mechanical, biological, esthetic

we want to be in the center of that venn diagram with our restorative work; sometimes we have to sacrifice one of those principles to get a better overall result

Question 11

what can happen if you take an alginate impression, then immediately rinse it off and put it in a plastic bag?

Answer 11

it can take on water (imbibition)

Question 12

what are the 3 types of resin cements?

Answer 12

adhesive, self-adhesive, esthetic

Question 13

what is an example of a self adhesive resin cement?

Answer 13

relyX unicem

Question 14

of adhesive, self adhesive, and esthetic resin cements, which is has the strongest bond?

Answer 14

adhesive

Question 15

of adhesive, self adhesive, and esthetic resin cements, which has to be used with a bonding agent?

Answer 15

esthetic

it will be incredibly strong, but not as strong as adhesive

Question 16

what is bis-acryl used for?

Answer 16

temporary material

Question 17

___ is a temporary material that has good color selection, but the shelf life is not very good. why?

Answer 17

• bis-acryl
• the colors start to darken after the expiration date

Question 18

bis-acryl is a ___-based resin material

Answer 18

bis-GMA

Question 19

would you want to use bis-acryl for a bridge? why or why not?

Answer 19

no

it is a big-GMA resin material and so it is brittle

triad material is better for bridges

Question 20

what is it that makes the outer layer of bis-acryl gummy after polymerization?

Answer 20

the oxygen inhibited layer

Question 21

when can you add to bis-acryl?

Answer 21

when the oxygen inhibited layer is still there

it is much more difficult if that layer is gone

Question 22

___ is a methylmethacrylate that has to be light cured to fully polymerize

Answer 22

unifast

Question 23

what is a disadvantage of unifast?

Answer 23

not great esthetically

Question 24

what are some advantages of unifast?

Answer 24

• handles very nice and is very forgiving
• good for contours of gingival embrasures where you feel like material might get locked in

Question 25

what type of matrix should you use with unifast?

Answer 25

alginate don't want to use the putty matrix

Question 26

\_\_\_ is the most esthetic version of zirconia. why?

Answer 26

high trans, because it has more zirconia in the cubic phase (this also means it's slightly weakened)

Question 27

\_\_\_ is the strongest phase of zirconia, and it is stabilized by \_\_\_

Answer 27

* tetragonal * yttria, ceria, and alumina

Question 28

what is the ideal length of a post, and how much gutta percha should be at the apex?

Answer 28

* 2/3 - 3/4 the length of the root * 4-5mm of gutta percha at the apex

Question 29

\_\_\_ posts tend to stress dentin at the coronal end, while ___ posts tend to stress dentin at the apical end

Answer 29

* tapered * parallel

Question 30

what happens to stress forces on dentin if you shorten a post?

Answer 30

it increases the stress forces

Question 31

is it ok to use a green stone to adjust zirconia?

Answer 31

no, because it will cause a phase change to monoclinic since it's not as strong of a material as zirconia

Question 32

transformation toughening is also called \_\_\_

Answer 32

crack propagation prevention

Question 33

transformation toughening occurs when a crack forms in zirconia, causing a phase change from ___ to \_\_\_

Answer 33

tetragonal to monoclinic, which is larger, so it makes it tougher and more resistant to more cracking

Question 34

zirconia can break down from certain insults like heat and friction. what is the phase change that occurs, and what can it cause?

Answer 34

* tetragonal to monoclinic * can cause fracture, increased abrasivity, low-temp aging degradation, increased hydrothermal solubility

Question 35

is build up material harder or softer than tooth structure?

Answer 35

softer

Question 36

is it ok to expose a pin while you are doing a buildup?

Answer 36

yes, but you don't want to cut the pin while doing it

Question 37

clinically, when delivering a crown, which is the first parameter to check?

Answer 37

proximal contacts

Question 38

what is scotopic vision and photopic vision?

Answer 38

* scotopic - rods * photopic vision - cones

Question 39

what type of vision do you use when doing shade matching?

Answer 39

scotopic (rods)

Question 40

when shade matching, if you're going to err, you should err on the light or dark side, and why?

Answer 40

light side, because it's much easier to darken a light shade rather than lighten a dark shade

Question 41

the surface of what tooth has the most dominant hue?

Answer 41

cervical 1/3 of an unrestored upper canine

Question 42

T or F you should never cut dry using a high speed handpiece

Answer 42

false while it is really important to keep teeth wet to avoid friction heat with high speed handpieces, it is acceptable to cut dry on a non-vital tooth, or on a vital tooth if the RPMs are really low (i.e. stall-out) and if the tooth is kept moist intermittently \*you can also cut dry with a slow speed

Question 43

what is the liquid component of IRM?

Answer 43

eugenol (oil of cloves)

Question 44

\_\_\_ is a good temporary material to put on a pulp exposure of a tooth that needs endo. it keeps the tooth "calm" enough until completion of the root canal.

Answer 44

IRM (ZOE + acrylic powder + eugenol)

Question 45

ZOE + acrylic powder + eugenol = \_\_\_

Answer 45

IRM (intermediate restorative material)

Question 46

what should you do if you get a pulp exposure on a direct restoration, like an MO?

Answer 46

it needs to remain uncontaminated by saliva and other things, and must remain moist chances are fairly good at this point to do a pulp cap and the tooth may never need endo

Question 47

what should you do if you get a pulp exposure on an indirect restoration?

Answer 47

the risk is too high for a direct pulp under indirect restorations, so you'll want to do an indirect pulp cap or RCT depending on how deep the pulp exposure is

Question 48

\_\_\_ is the liquid component of zinc polycarboxylate

Answer 48

polyacrylic acid

Question 49

does polyacrylic acid cause pulpal sensitivity? why or why not?

Answer 49

no, because it's too bit to penetrate dentin tubules

Question 50

polyacrylic acid is fundamental in the development of \_\_\_

Answer 50

glass ionomer cement

Question 51

polyacrylic acid is found in ___ and \_\_\_, and is used as a conditioner liquid for \_\_\_

Answer 51

* polycarboxylide cements and glass ionomer cements * resin modified glass ionomer cements

Question 52

\_\_\_ describes a material that maintains the same size as it sets and as it's removed from the mouth

Answer 52

dimensional accuracy

Question 53

\_\_\_ is how long a material stays the same size without distorting

Answer 53

dimensional stability

Question 54

\_\_\_ is an impression material's ability to rebound back to proper dimensions

Answer 54

elastic recovery

Question 55

putty material is an example of what type of impression material?

Answer 55

condensation silicone, which is a type of elastomer

Question 56

what is the biproduct of condensation silicones, and what is their best use?

Answer 56

* ethyl alcohol * silicone matrices only

Question 57

PVS is what type of impression material?

Answer 57

addition silicone, which is a type of elastomer

Question 58

what is the biproduct of PVS? what is the scavenger? what is the problem with cheaper PVS materials?

Answer 58

* hydrogen gas * palladium * cheaper materials don't have the scavenger so you need to let it sit for a while so that the H2 gas doesn't produce air bubbles

Question 59

sulfur compounds (latex gloves) should not be used with what impression material?

Answer 59

PVS

Question 60

polyether is what type of impression material?

Answer 60

elastomer

Question 61

what are 3 disadvantages of polyether?

Answer 61

* most rigid of all the elastomers * terrible taste * dimensional stability is not on par with PVS

Question 62

which elastomer has a terrible smell, is accurate, you want to pour it quickly, and cannot be used for more than one pour?

Answer 62

polysulfide rubber base | (not used very often)

Question 63

\_\_\_ describes tissue at the attachment apparatus that is very thin and more susceptible to recession

Answer 63

thin biotype

Question 64

\_\_\_ describes tissue at the attachment apparatus that is very thick, including robust crestal bone, and is less susceptible to recession

Answer 64

thick biotype

Question 65

for anterior **zirconia** crown preparation, what are the reduction measurements for the following? facial depth at margin lingual depth at margin lingual concavity incisal reduction

Answer 65

* facial depth at margin - 0.5-1.0mm * lingual depth at margin - 0.5-1.0mm * lingual concavity - 1.0-1.5mm * incisal reduction - 2.0-3.0mm

Question 66

for anterior **lithium disilicate** crown preparation, what are the reduction measurements for the following? facial depth at margin lingual depth at margin lingual concavity incisal reduction

Answer 66

* facial depth at margin - 1.0-1.5mm * lingual depth at margin - 1.0-1.5mm * lingual concavity - 1.5-2.0mm * incisal reduction - 2.0-3.0mm

Question 67

which type of stone is use as a mounting stone and has the least amount of expansion upon setting?

Answer 67

type I

Question 68

type ___ dental stone is used mostly as impression stone

Answer 68

III

Question 69

type ___ dental stone is a die stone and is not as hard as type V

Answer 69

IV

Question 70

type ___ dental stone is a die stone, expands a lot, is very hard, and is used for ceramo-metal restoration

Answer 70

V

Question 71

\_\_\_ can be added to stones to increase abrasive resistance

Answer 71

thin cyanoacrylate

Question 72

hydrocal and densite are both \_\_\_-hemihydrate

Answer 72

alpha

Question 73

hydrocal is used to make type ___ dental stone

Answer 73

III

Question 74

densite is used to make type ___ dental stone

Answer 74

IV and V

Question 75

beta-hemihydrate is used to make type ___ dental stone

Answer 75

I and II

Question 76

alpha-hemihydrate is used to make type ___ dental stone

Answer 76

III (hydrocal), IV (densite), and V (densite)

Question 77

how does glass ionomer adhere to tooth structure?

Answer 77

carboxylate (in cement) and calcium (in tooth) ionic bond

Question 78

\_\_\_ is the liquid component of zinc polycarboxylate

Answer 78

distilled water

Question 79

how does zinc polycarboxylate adhere to tooth structure?

Answer 79

calcium chelation bonds

Question 80

what is hue, chroma, and value?

Answer 80

* hue is the color (ex. blue vs. red vs. yellow), determined by the wavelength of the reflected and/or transmitted light observed * chroma is the intensity of the hue (aka saturation, strength of hue, concentration of pigment) * value is the relative lightness or darkness of a hue

Question 81

does a higher value correspond to a lighter or darker appearance?

Answer 81

lighter

Question 82

\_\_\_ is the phenomenon of two colors that match under one set of conditions, but fail to match under a different set

Answer 82

metamerism

Question 83

does a base strengthen the tooth?

Answer 83

no, its purpose is getting back to an ideal prep, and also serves as a thermal insulator

Question 84

what does a liner provide?

Answer 84

chemical barrier \*not\* a thermal insulator

Question 85

what do build-ups do?

Answer 85

increase attachment/connection between a restoration and the tooth

Question 86

if given the choice, would you want to use a post?

Answer 86

no (iatrogenic fracture)

Question 87

what are posts used for?

Answer 87

they enhance the connection between the tooth and the restoration