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Flashcards in Fixed Q4 Deck (86):
1

What is worse, an open margin or an over-contoured crown?

Over contoured

(plaque trapped underneath)

2

What is the most critical and neglected aspect of occlusion?

Lateral excursive movements

3

Most errors in crown contours are found where?

Embrasure spaces

4

If crown is deficient, how would you add matl IP or occlusally?

Ceramic - stack low fusing porcelain

Metal - solder

5

What type of luting material needs anesthesia?

What type strengthens restorative material?

Bonded Resins

(for both)

6

What is the advantage to a Luted crown?

What is the disadvantage of a Bonded crown?

sectioned and removed easily

prepped off

7

What type of cement will increase the flexural strength of glass ceramic crowns?

Adhesively bonded resin

8

T/F
You can bond zirconia and metal

False

*crystal/metal won't adhere to bonding agent

9

For emax, would you lute or bond if you lacked resistance form?

bond

10

For emax, if you can't isolate, would you lute or bond?

lute

*adhesive cement very difficult if can't isolate

11

T/F
Bonding strengthens, holds over time better but if you have retention/resistance you often don't need it

True

12

T/F
Bonding is very difficult to remove and more technical to apply

True

13

Name 3 advantages to luting with RMGI:

postcementation sensitivity minimal

higher strength than normal GI

strength similar to resin luting agents (but not really)

14

Zinc Phosphate has a film thickness of ___ um, is easy to clean, and has a long track record of success

25

15

What has better biocompatibility than Zinc Phosphate b/c polyacrylic acid molecule is large and does not penetrate into the dentinal tubules?

Zinc Polycarboxylate

16

What luting agent is superior to Zinc Phosphate and Zinc Plycarboxylate and is susceptible to moisture?

GI

17

What luting agent is extremely biocompatible but has mechanical properties inferior to other cements?

Zinc Oxide Eugenol

18

Why are resin cements susceptible to incomplete seating?

High film thickness

19

2 goals of provisional cements?

seal margin

prevent leakage/pulpal irritation

20

What type of provisional cement does ASDOH use?

tempbond NE - zinc oxide bases cement

*NE stands for Non-Eugenol

21

Why is Eugenol bad in resins?

free radical scavenger that can inhibit resin setting

22

Normal Provisional cement we use is tempbond NE, what is the stronger one we use?

What type of cement is it?

Durelon

Polycarboxylate

23

Sequence of check when seating a crown:

IP

Margins

Occlusal

Contour

Esthetics

24

If crown isn't seated all the way and you adjust the occlusal contacts, you will be in...

Hypo-occlusion

25

Check IP contact with...

accufilm

26

A removeable die system is set in Type ___ gypsum, and it can abrade the IP contacts so adjustments are made on another poured up non-removeable system

IV

27

You can't get an explorer in all IP contacts, so what to do?

If you don't have adjacent teeth, do you still need to take a radiograph?

Radiograph

NO - not if detectable with an explorer

28

How thick is accufilm?

21 microns - fold over technique to see how much to grind (by measuring adjacent teeth to the one in hyperocclusion)

29

Sequence to bond a veneer:

Veneer

HF

Silane

Bonding (No primer)

luting

Bonding (w/ primer)

HPO4

Veneer prep

30

What is the purpose of a primer?

Why don't use on veneer?

Hydrophilic to hydrophobic

no dentin - no need

31

We can't use adhesive bonding if the Intaglio is...

Metal or Crystal

*so no zirconia, no PFM

32

Would we lute or bond empress?

Bond

-will increase strength

33

Would we lute or bond emax?

Either

- if min. occlusal thickness bond
- if good retention/resistance lute

34

Why do we add grooves and boxes to a gold crown prep?

Irregularities help luting agent - and prevents leakage

35

Brand name of the RMGI we use to lute in clinic:

FujiCEM

*increases strength, lowers solubility

*RMGI is still considered luting

36

In an endo tooth - If 3 or more walls have a 1mm thickness following crown prep, do what?

Chamber retained core buildup

37

When should a post be used in an endo tooth?

Retention inadequate

*two walls or less

38

To put Amalgam in a core buildup, how thick should the wall be after a prep is made?

1 mm

39

What type of build up is used for multi-rooted teeth that have gone through endo?

Chamber retained core build up

*has dentin thickness and pulp chamber adequate

40

The height of a core build up has to be at least what?

4 mm

*either height of pulp chamber or into root canal

41

As a core material composite has a _____ CTE

____ modulus of elasticity

Bonding to denting that is _____

high

low

not strong

42

What is the disadvantage of GI as a core material?

Strength

*also moisture sensitive and low tensile strength

43

What is the purpose of a Post?

What does it NOT do?

retain core build up

reinforce tooth

44

A post should only be considered to retain core build up when?

all other forms of retention are inadequate

*only two walls

45

A post is ideally ____ the length of the root

An apical seal of at least ___mm of GP is to remain

2/3

4mm

46

What is more important, 4mm of GP remaining when placing post or it being 2/3 of the length of root?

4mm

47

Post diameter should be limited to ____ the root diameter

1/3

48

T/F
Strength of an endo treated tooth is directly related to bulk of dentin structure

True

49

What type of post leads to higher fracture rates?

Active

*screwed in

50

What type of Post has enhanced esthetics, excellent biocompatibility, mechanical properties similar to dentin, easy to use/remove, firm retention with adhesive, and lower radiopacity than a metal post?

Fiber reinforced

51

Two types of Posts:

Fiber and Metal

52

How is a Metal post placed?

Fiber?

Luted

Bonded

53

What type of Post is one piece, high cost, and technique sensitive?

Cast

54

How big should a ferrule be?

2-3mm

55

What is the function of a ferrule?

reduces tooth fracture

56

Mechanical loading will produce cracks that progress in what direction?

Coronal to Apical

57

Fatigue failure is more catastrophic in what type of tooth?

Nonvital

*complete root fracture may occur

58

Libman Nichols found that Ferrule length worked better at 1.5mm than 2mm - why?

2mm had to cut tooth structure down, lowering C/R ratio

59

Ideal Crown to Root ratio:

Minimum:

2:3

1:1

60

If we have less than 1:1 Crown to Root ratio, what type of occlusal trauma will ensue?

Secondary - reduced peridontium

61

In upper anterior teeth, what wall is the most critical in reducing load fracture?

Palatal

62

We want how many mm of Ferrule above the margin?

2mm

63

T/F
Ferrule effect is for resistance/retention

False

*designed to prevent tooth splitting

64

2 techniques to gain adequate tooth structure:

Crown lengthening

Orthodontic extrusion

65

Crown to Root ratio better with extrusion and crown lengtheing

Yes?

66

Junctional Epithelium + Connective Tissue

Biologic Width

67

On average we want __ mm from the bone to where the core material starts

5

*2 bio width +1 sulcus +2 Ferrule

68

One article concluded that a post doesn't strengthen a tooth, but weakens it

True

69

Do you have to crown a tooth that has been endo treated?

No

70

Endo Tx teeth last how long?

1-25 years

71

Sorensen et al concluded that _____ didn't significantly improve that rate of clinical success for Mx and Mb teeth

Coronal coverage of anterior teeth

72

Sorenson et al concluded that intracoronal reinforcement (a post) didn't do what?

increase resistance to fracture

73

The purpose of a post:

Retain core build up

74

Bridge, aka

FPD - fixed partial denture

75

FPD, dummy tooth:

Crowns:

Crown prep:

between dummy tooth and crowns:

Pontic

Retainer

Abutment

connector

76

Ante said that the combined pericemental area (root structure) should be greater than or equal to the area of the teeth being replaced

True

*all root area

77

Does an FPD have to fulfill Ante's Law?

No

*most don't and are fine

*now it's more like Ante's Guideline

78

an FPD only one side of which is attached to a retainer

Cantilever

79

Why is a Cantilever not ideal?

Doesn't direct forces along long axis of the tooth

*why generally don't do and recommend implants instead

80

Greatest failure rate in Sorensen study was pulpless (endo Tx) teeth with?

No crown

81

3 reasons a tooth needs a crown:

Tooth structure

Improve esthetics

change contours

82

A crown that supports a removable partial denture (RPD)

Survey Crown

83

RPD abutments fail 2x as often as FPD

True

84

A Post will decrease the success rate of an FPD

True

85

What tooth should be prepped 1st in FPD?

Smaller

(premolar rather than molar - errors can be corrected w/ greater tooth structure)

86

What instrument can detect undercuts when prepping an FPD?

Surveyor Instrument

*also CEREC

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