Comprehensive Final Flashcards Preview

Fixed Prosthodontics > Comprehensive Final > Flashcards

Flashcards in Comprehensive Final Deck (84)
Loading flashcards...
1
Q

What is the best combo as far as cement strength is concerned?

A

High compression strength and high elastic modulus (less stretchy)

2
Q

What side effect can pain stimuli have on salivary flow?

A

It increases it

3
Q

What property needs be reduced when dealing with PFM’s to reduce bond sheer strength?

A

Coefficient of thermal expansion

4
Q

Name properties of types III-V gypsum stone:

A

Type III: Low strength low expansion, Type IV: High strength low expansion, Type V: High Strength high expansion

5
Q

Why are PMM’s better for long span bridges?

A

Higher fracture toughness

6
Q

What makes an irregular crown margin undesirable?

A

Harder to read and more likey to cause recurrent decay

7
Q

What are advantages of a chamfered margin?

A

Distinct, easy to read, allows adequate bulk of material

8
Q

What three pieces of key information about a patient are NOT captured in a triple bite technique?

A

Contralateral tooth anatomy, tooth balancing issues, condylar inclination

9
Q

What is the result of an abraided dye margin?

A

Over-finished crown

10
Q

How should Calcium Hydroxide be used?

A

As a direct/indirect pulp cap - don’t do under crowns

11
Q

What chemical mechanism allows for Polycarboxylate cements to bond to the tooth?

A

Calcium chelation

12
Q

What is the key to trimming bite registration?

A

Keep it perpendicular

13
Q

What are the three variables of color?

A

Chroma, hue, and value

14
Q

Where is the color of the teeth best determined?

A

Cervical region of the upper canines

15
Q

Does increasing surface roughness of the prepared tooth increase retention?

A

No

16
Q

Why use a coarse diamond?

A

They cut cooler

17
Q

What height must a ferrule be to be effective?

A

2 mm

18
Q

Why don’t we use self-adhesive cements for bonding partial coverage posterior ceramic restorations?

A

Due to bond strength (we use aesthetic resin cements)

19
Q

Does light activation make a difference in the properties of self-adhesive cements?

A

Yes, catalyst causes color change over time (and should be used therefore in the posterior)

20
Q

With a shortened dental arch, what characteristic was associated with an increase in joint sounds?

A

Posterior missing on one side

21
Q

Compare solubility of resin, glass-ionomer and zinc phosphate?

A

Zn phosphate is most, GI is second and resin is least soluble

22
Q

Self-adhesive cement Rely-x Unicem, how does it not need acid?

A

Acid is already inside the cement and it neutralizes in the set time

23
Q

What are the two resin-modified GI’s used in the clinic?

A

Fujisim and RelyX 3M+

24
Q

What do you use to cement a post in the clinic?

A

RelyX unicem

25
Q

What is the problem with bonded EMax?

A

None

26
Q

What is the problem with bonded Zirconia?

A

No retrievability

27
Q

Are residual walls of a devitalized pulp chamber an accessible feature?

A

Yes

28
Q

Where is GI chemistry commonly found in dentistry?

A

Direct fill, cements, sealants, buildups and foundations (You don’t find them in varnishes and de-sensitizers)

29
Q

Ideal minimum anterior all-ceramic crown on the lingual concavity?

A

1.5 mm

30
Q

What is the amount of axial reduction?

A

1.2-1.7 (PFM) and 1 mm for solid porcelain (Emax) and .5 for Zirconia

31
Q

What is the amount of reduction in a posterior PFM all over?

A

2.0 mm

32
Q

Which is the most ideal material design for Zirconia crowns?

A

Gold prep 0.5-1.0 mm, 1.5 on non-functional and 2.0 on functional cusps

33
Q

What about all-ceramic posterior reductions?

A

2.0 mm

34
Q

What is the minimum metal thickness in a PFM?

A

0.3 mm

35
Q

How do you remove non-bonded crown restorations?

A

Sectioning the crown (bonded need to be ground down)

36
Q

What metal is frequently confused with the noble metals but is not?

A

Silver

37
Q

Why is a full-coverage crown more retentive?

A

Opposing axial walls are used in retention

38
Q

What is the ideal range of taper?

A

6-10 degrees

39
Q

What is the acceptable range of taper?

A

5-22 degrees

40
Q

What variable will always increase retention, but may not increase resistance?

A

Surface area

41
Q

What are some retentive features?

A

Boxes, isthuses and grooves

42
Q

Which is more important, internal or external axial retention?

A

Neither - they are both equally important

43
Q

Why is the marginal gap in the PFM worse than gold?

A

Porcelain contracts at the end of the firing cycle

44
Q

What is the best fit for a crown?

A

10 microns

45
Q

Why is it important to have close marginal adaptation?

A

Less dissolution of luting agent, perio disease, smooth transition, recurrent caries

46
Q

Zinc oxide is in a bunch of different cements – name them:

A

ZOE, IRM, EBA, (only ones its not in is GI and resins)

47
Q

What is important to know about Eugenol?

A

That it is an obtundant

48
Q

Name cements that you get sustained Fluoride release:

A

GI, Silicates, RMGI

49
Q

With VITA classic shade guide, what is the order in which the color parameters are found?

A

Hue, Chroma, value

50
Q

How are the surroundings critical in shade selection?

A

Pastel colors (less than 4 units in chroma)

51
Q

What is Metamerism?

A

When different lighting can cause colors to appear differently

52
Q

Why should we squint or glance at colors?

A

To engage our scotopic vision - in other words, to utilize the area with the most rods for value determination

53
Q

Which color disappears last with squinting?

A

The one with the highest value

54
Q

When do we NOT use a butt margin veneer in the anterior?

A

When we are working on the lower incisors

55
Q

When do we use a window prep for veneers?

A

When we are working with the posterior teeth

56
Q

What are the two keys to using a reduction guide well?

A

Cut it into 3 pieces and refer to it often

57
Q

What post and core is the strongest?

A

Cast post and core

58
Q

What is the downside to using cast post and core?

A

When they fail, the tooth is doomed

59
Q

What is the guideline in posterior partial coverage with minimum amount of enamel?

A

Some enamel must remain on the buccal and lingual

60
Q

Of all the resin cements which doesn’t have a light cure option?

A

Adhesive resin cements

61
Q

When can viscosity become a problem?

A

When the cement is going into the set phase

62
Q

What could be the possible consequences of cement becoming more viscous?

A

It doesn’t set all the way as a crown or distortion in impressions (shrunken dye)

63
Q

What are the primary objectives of a complete occlusal adjustment?

A

No incline contact, try to direct forces axially. Seat condyles, axially directed forces and everything off the inclines, get the guidance as far to the anterior

64
Q

If you were doing a buildup and you had a high chance of moisture what is the best?

A

Low copper amalgam

65
Q

Which tooth preparation requirement (resistance, retention, anti-deformation) does occlusal reduction fit into?

A

Anti-deformation

66
Q

What are the main advantages of a partial coverage posterior ceramic?

A

Conservation of tooth structure, buccal/lingual tooth structure is good, aesthetics

67
Q

What are the two main disadvantages of composite resin material as a buildup?

A

Moisture absorption and high thermal expansion

68
Q

Most important bottom line factor in longevity of endo-treated crowns is?

A

An occlusal scheme that limits non-axial loading

69
Q
  1. Of all retentive features that we can do (pins, posts, etc), which have the highest iatrogenic failures?
A

Pins

70
Q

Propantholin – the anti-sialogog – where do you have to be careful using it?

A

If the patient has glaucoma

71
Q

What are the factors that determine final shape of the prepared tooth?

A

Morphology, ideal reduction, opposing occlusion, damage to existing tooth and restorative material and attending dentist

72
Q

What is the one thing that you have to remember with electrosurgery?

A

There will be tissue shrinkage beyond the cut point

73
Q

What are the hemostatic agents?

A

Viscostat (Aluminum chloride) and Stringadent (Ferricsulfate) and also (not in clinic) as a hemostatic agent anesthetic

74
Q

Contact angle – what is it in impression?

A

Beading of the water, high contact angle, hydrophobic has high angle

75
Q

Understand when the shortened dental arch research can and cannot be applied:

A

Age, # teeth, perio, occluding units, motivation, oral hygiene, no wear on their teeth

76
Q

Stress breakers – why and when do you need them?

A

Peer abutments (fulcrum), mandibular long-span bridge that crosses the midline, extremely off-axis bridge abutment teeth, it can allow you to reduce less tooth structure

77
Q

What are some reasons for sub-gingival margin placement?

A

Esthetics, caries/damage to the tooth, retention

78
Q

Criteria for using a triple tray in the posterior:

A

2 opposing prepared teeth (ok), 2 teeth in the same arch (ok), 3 teeth/bridges (not okay), esthetic case (not okay), canines/2nd molars (not okay)

79
Q

With pontics, from a biological standpoint what is the best shape?

A

Convex in every direction (some concavity can be done on the facial)

80
Q

Most esthetic pontic:

A

Ovate

81
Q

What are the cements that chemically bond to tooth structure?

A

All resins, GIs, RMGIs, Polycarboxylate, (Zn-phosphate can not, EBA can not)

82
Q

If a crown rocks buccal/lingually, where is the first place you go to check?

A

Interproximal contacts

83
Q

What are things that can prevent crown seating (besides interproximal contacts)?

A

Nodules, intaglio surface

84
Q

One last thing about the 7/8’s crown, there was a unique feature call the occlusal offset – what did it do?

A

Added strength, esthetics (gold thinner), creates a staple effect