Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

SP14 - Fixed Restorative > Lab Manual Quiz > Flashcards

Lab Manual Quiz Flashcards

questions taken from Chapters 1-7 of the lab manual

1
Q

Define preparation.

A

the final shape (form of the tooth) produced by instrumentation, to receive a restoration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Define complete veneer crown preparation.

A

extracoronal preparation involving the entire clinical crown

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Define complete veneer crown (CVC).

A

a cast-gold extracoronal restoration which covers the clinical crown

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Define path of withdrawal (POW).

A

imaginary line along which a casting is moved when it is separated from its prepared tooth; for single crowns, it should correspond with the long axis of the tooth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Define axial wall.

A

part of a crown preparation prepared in the long axis of the tooth (buccal, lingual, mesial, or distal)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Define convergence angle.

A

the angle or taper formed by diametrically opposed axial walls

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Define chamfer.

A

the cervical junction of the prepared axial wall and the unprepared portion of the tooth structure; it extends around the most cervical portion of the tooth preparation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Define axial wall line angle.

A

the junction between any two axial walls

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Define occlusoaxial line angle.

A

the junction between the occlusal surface and an axial wall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Define cavo-surface line angle.

A

the junction of prepared to unprepared tooth structure; external line angle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Define depth orientation grooves.

A

grooves placed on the surface of the tooth to provide a reference to determine when sufficient tooth structure has been reduced

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Define functional cusp bevel.

A

a wide bevel placed on the functional cusps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the purpose of a functional cusp bevel?

A

the thickness of the tooth structure removed when preparing this bevel ensures that correct contours of the final restoration can be re-established while providing correct convergence and adequate thickness of restorative material

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Which cusps are the functional cusps?

A
  • mandibular - buccal cusps

- maxillary - lingual cusps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Define undercut.

A

a crown preparation is undercut if a wax pattern cannot be withdrawn from its die without distortion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the 2 causes of an undercut? How can each be fixed?

A
  • a depression in an axial wall, caused, for example, by a carious lesion; can be corrected with a base material
  • diametrically opposed axial walls that do not converge occlusally caused by improper angulation of the cutting instrument; requires further tooth reduction to fix
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Define occlusal clearance.

A

the distance between the occlusal surface of the prepared tooth and the occlusal surface of the opposing tooth; this clearance must be evaluated during excursive jaw movements as well as in intercuspal position

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Define retention form.

A

the characteristics of the tooth preparation which tends to resist the removal of a restoration along its path of withdrawal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Define resistance form.

A

the characteristics of a tooth preparation which tends to prevent dislodgement of a seated restoration by forces directed in an apical or oblique direction; prevents dislodgement of the restoration by occlusal forces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the advantages of a complete veneer crowns?

A
  • high strength
  • longevity
  • high resistance to displacement
  • ability to modify axial contours and occlusion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the disadvantages of complete veneer crowns?

A
  • display of metal
  • removal of tooth substance
  • vitality testing
  • margin close to gingival tissue
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are some indications for complete veneer crowns?

A
  • extensive destruction by caries or trauma
  • endodontically treated teeth
  • large existing restoration
  • maximum retention needed (ex. long span fixed partial denture abutment)
  • recontouring of axial surfaces
  • correction of malinclination
  • correction of occlusal discrepancies
  • to provide contours suitable for a removable partial denture
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the contraindication for complete veneer crowns?

A

wherever a tooth can be adequately restored with a more conservative restoration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the principles of tooth preparation for CVCs?

A
  • conservation of tooth structure
  • marginal integrity of the restoration
  • retention and resistance
  • structural durability
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are 4 ways inadequate marginal integrity can occur in a CVC prep?

A
  • chamfer is too narrow to provide sufficient bulk of restorative material without over-contouring
  • the cavo-surface line angle cannot easily be determined during laboratory procedures
  • the chamfer is rough or uneven
  • the preparation is undercut causing distortion of the wax pattern
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are 3 ways inadequate retention and resistance form may occur in a CVC prep?

A
  • excessive convergence angle
  • inadequate height and surface area of the axial walls
  • insufficient surface area to resist tipping of the restoration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the recommended depth of a functional cusp reduction?

A

1.5 mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is the recommended depth of a central groove reduction?

A

1.0 mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is the recommended depth of a non-functional cusp reduction?

A

1.0 mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is the recommended width of the chamfer?

A

0.5 mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What convergence angle is formed by the taper of a 242.6M bur?

A

3-4 degrees from cervical to occlusal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is the sequence of steps of tooth reduction that will be used in the complete veneer crown preparation?

A

1) occlusal guiding grooves
2) occlusal reduction
3) axial guiding grooves
4) axial reduction
5) finishing and evaluation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

If you are prepping tooth #30 for a CVC, which teeth should be included in the silicone reduction guide?

A

28 - #31

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Where is a silicone reduction guide cut?

A

from mid-buccal to mid-lingual of the tooth being prepped

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is the dimension of the interproximal chamfer placement (margin clearance interproximally) for a CVC prep of tooth #30?

A

0.5 mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

In a CVC prep of tooth #29, how many guide grooves are placed in the axial wall of the buccal and linual sides?

A
  • 3 guide grooves on the buccal axial wall

- 3 guide grooves on the lingual axial wall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What bur is used to remove the last few milimeters of tooth structure interproximally in a CVC prep of tooth #29?

A

an extra thin 747.6M diamond bur

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

With what bur is the chamfer (including interproximally) refined?

A

L-242.6M diamond bur

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

True or false: When finishing a CVC prep, the prep should have a polished surface.

A

FALSE. A polished surface is unacceptable; there should be light striations in the finish.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

When doing a CVC prep for tooth #20, what teeth should be covered by the silicone reduction guide?

A

18 - #22

41
Q

Which cusps are the functional cusps on a maxillary molar?

A

lingual cusps

42
Q

What is Aluwax used to measure?

A

occlusal clearance after completing the occlusal reduction

43
Q

How many planes of reduction does the buccal surface of a maxillary posterior tooth have?

A

2

44
Q

Describe the planes of reduction of the buccal surface of a maxillary posterior tooth.

A
  • first plane - from the gingival crest to about the junction of the middle and occlusal third of the tooth
  • second plane - from the junction of the middle and occlusal third of the tooth to the occlusal edge
45
Q

Which plane of reduction on the buccal surface of a maxillary posterior tooth establishes the path of withdrawal?

A

buccal first plane of reduction

46
Q

Which plane of reduction on the buccal surface of a maxillary posterior tooth is reduced to provide sufficient space for the restoration metal?

A

both the first and second planes of reduction

47
Q

Which plane of reduction on the buccal surface of a maxillary posterior tooth is reduced to restore the tooth to its original contour?

A

buccal second plane of reduction

48
Q

True or false: The buccal second plane reduction on a maxillary posterior tooth is carried interproximally.

A

FALSE. It is not carried interproximally because it would overconverge the occlusal 1/3 of the mesial and distal proximal axial walls.

49
Q

What is the ideal dimensions of a buccal second plane reduction on a posterior maxillary tooth?

A

1.0 mm

50
Q

“Each provisional restoration should be made with the idea that _____________________.”

A

it can adequately protect the patient for an extended time period (of the order of months anyway).

51
Q

What are the 5 biologic provisional restoration requirements?

A
  • protect pulp
  • maintain periodontal health
  • provide occlusal compatibility
  • maintain tooth position
  • protect against fracture
52
Q

What are the 3 mechanical provisional restoration requirements?

A
  • resist functional loads
  • resist removal forces
  • maintain interabutment alignment
53
Q

What are the 4 esthetic provisional restoration requirements?

A
  • easily contourable
  • color compatibility
  • translucence
  • color stability
54
Q

What two forms are assembled to make a mold cavity when making provisional restorations?

A
  • tissue surface form

- external surface form

55
Q

What are the 3 categories for a tissue surface form?

A
  • indirect
  • indirect-direct
  • direct
56
Q

Which type of tissue surface form is preferred when making a provisional restoration?

A

indirect

57
Q

How is the external surface form normally developed?

A

diagnostic waxing procedure

58
Q

True or false: In the clinic, the external surface form should be made during the patient’s appointment.

A

FALSE. The external surface form should be made prior to the patient’s appointment.

59
Q

Describe the steps for producing an external surface form in lab for tooth #3.

A
  • use a typodont with unprepared teeth
  • make an alginate impression of the whole arch
  • pour fast-setting plaster into the impression
  • after 20 min, trim it for use as a vacuum-form mold
  • vacuum-form a polypropylene sheet on this “diagnostic cast”
  • trim to the distal of tooth #2 and mesial of tooth #6; the buccal and lingual extension should be trimmed with scissors 3 mm from the gingival margin in order to form an adequate seal around #2-6
60
Q

Describe the steps for producing an internal surface form for tooth #3.

A
  • choose an impression tray for an irreversitble hydrocolloid impression (needs to extend 2 teeth beyond the tooth)
  • place prepared tooth #3 into typodont
  • if necessary, use cord to displace rubber gingival tissue to expose the cavosurface margins
  • make an irreversible hydrocolloid impression
  • pour impression in fast-setting plaster and wait 20 minutes
61
Q

Describe the procedure for fabricating an indirect provisional crown for tooth #3.

A
  • remove the cast of the prepared tooth #3 and trim it to provide proper indexing with the external surface form; check that the two forms fit together!
  • paint the cast with one layer of separating medium (Al-Cote)
  • when dry, lightly mark the cavosurface margins of the preparations with a soft lead pencil (repaint margins with separator if you have removed the previously applied coat with the pencil)
  • mix Jet autopolymerizing resin (a methyl-methacrylate) and use a 8A or cement spatula to carry the resin to the polypropylene external surface form
  • fill the external surface form methodically, starting at one end of the restoration and working to the other (to avoid air bubbles, add only to existing resin); resin should reach the level of the gingiva
  • seat the cast of the prepared tooth in the filled external surface form (hold together with rubber band, not over tooth #3)
  • place the assembly in warm water in pressure vessel; apply air at about 0.15 Mpa (pressure curing reduces resin porosity)
  • remove assembly after 15 min
  • separate the external surface form from the cured resin; the bulk of the stone can be removed on a cast trimmer and with a Carborunum disk
  • remove resin flash with an acrylic-trimming bur and fine-grit garnet paper disk
  • polish the restoration with wet pumice and acrylic resin-polishing compond
62
Q

What is evaluated about the proximal contacts in the evaluation of a provisional restoration?

A
  • presence
  • contour
  • location
63
Q

What is evaluated about the axial contours in the evaluation of a provisional restoration?

A
  • faciolingual profile
  • line angle location
  • embrasure form
64
Q

What is evaluated about the pontic in the evaluation of a provisional restoration?

A
  • height
  • gingival surface contour
  • facial contour
  • lingual contour
65
Q

What is evaluated about the occlusion in the evaluation of a provisional restoration?

A
  • maximum intercuspation
  • protrusive
  • lateral
66
Q

What is evaluated about the margins in the evaluation of a provisional restoration?

A
  • fit

- contour

67
Q

What is evaluated about the finish in the evaluation of a provisional restoration?

A
  • porosity

- smoothness

68
Q

When making a provisional restoration, why is the resin cured under pressure?

A

pressure curing reduces resin porosity

69
Q

What portion of a metal-ceramic crown is metal and what is porcelain?

A
  • facial and occluso-buccal surface are porcelain

- the remainder of the crown is metal

70
Q

How far should the shoulder margin extend interproximally in a MCC prep?

A

from a point approximately 1 mm lingual to the mesiobuccal line angle, around the buccal surface, to a point approximately 1 mm lingual to the distobuccal line angle

71
Q

Why is the shoulder of a MCC prep extended past the mesio- and distobuccal line angles?

A

allows the porcelain veneer far enough interproximally to mask the metal contact area

72
Q

True or false: The shoulder recess should maintain a uniform width around its entire circumference.

A

true

73
Q

True or false: In mandibular posterior teeth, the proximal extent of the shoulder in a MCC prep can often stop just lingual to the proximal contact area.

A

FALSE. It stops just buccal to the proximal contact area because the esthetic demands for mandibular teeth are not as high as maxillary teeth.

74
Q

If the occlusal surface of a mandibular posterior tooth is covered with porcelain, how is the occlusal reduction changed?

A

the occlusal surface must be reduced at least another 0.5 mm

75
Q

What are the 3 major disadvantages to covering the occlusal surface in porcelain?

A
  • it has the potential to abrade opposing natural dentition
  • the potential for failure due to fracture under heavy occlusal loads is increased
  • more removal of tooth structure is required
76
Q

For MCC preps, what is the purpose of the buccal first plane?

A
  • establishes the path of withdrawal for the crown

- provides space for the veneering medium

77
Q

For MCC preps, what is the purpose of the buccal second plane?

A

reduced to provide for a uniform thickness of porcelain

78
Q

The typodont buccal second plane of a MCC prep is usually what fraction of the occlusal-cervical height of the buccal surface after occlusal reduction?

A

1/3 - 1/2

79
Q

What determines the angle of the buccal second plane of a MCC prep?

A

the depth orientation grooves which are the same as the original facial surface

80
Q

What 2 problems will over-convergence cause?

A
  • loss of retention form

- loss of resistance form

81
Q

For a mandibular posterior MCC restoration, what is the final reduction of the buccal (functional) cusp?

A

1.5 mm

82
Q

For a mandibular posterior MCC restoration, what is the final reduction of the lingual (non-functional) cusp?

A

1.0 mm

83
Q

For a maxillary posterior MCC restoration, what is the final reduction of the buccal (non-functional) cusp?

A

1.5 mm (although non-functional cusp, need to allow room for porcelain and metal substructure)

84
Q

For a maxillary posterior MCC restoration, what is the final reduction of the lingual (functional) cusp?

A

1.5 mm

85
Q

For a maxillary or mandibular posterior MCC restoration, what is the final reduction of the central groove?

A

1.0 mm

86
Q

What diamond bur is only used for MCC preps and what is it used for?

A
  • 702.8M diamond bur

- designed to prepare the shoulder through its flat end

87
Q

On the buccal and occlusal surfaces of a finished MCC restoration, what is the thickness of porcelain and metal substructure?

A
  • 1.0 mm thickness of porcelain

- 0.5 mm thickness of metal substructure

88
Q

What is the sequence of tooth reduction for a MCC prep?

A
  • occlusal reduction
  • buccal reduction
    • buccal first plane
    • buccal second plane
  • lingual reduction
  • proximal reduction
  • shoulder finish line (1.2 mm wide)
  • finishing and rounding of line angles
89
Q

What bur is used to make the axial reduction guide grooves of the buccal first plane? Where are these guide grooves placed?

A
  • 702.8M diamond bur
  • 3 grooves: one in the mesio-distal center of the tooth, one as close to the mesial proximal contact as possible, and one as close to the distal proximal contact as possible
90
Q

How far cervically should the axial reduction guide grooves be placed for the buccal first plane?

A

0.75 mm coronal to the pencil line

91
Q

Where should the buccal second plane depth orientation grooves be placed in an MCC prep?

A

between the first plane grooves, angled with the occlusal half of the buccal surface

92
Q

True or false: During the MCC axial reduction, the shoulder is prepared no wider than the diameter of the bur.

A

true

93
Q

What bur is used for the buccal axial reduction of a MCC prep? What bur is used for the lingual axial reduction of a MCC prep?

A
  • 702.8M diamond bur

- 242.6M diamond bur

94
Q

True or false: The prepared mesial and distal walls of a MCC prep should not be parallel.

A

FALSE. The mesial and distal walls should be parallel.

95
Q

What instruments can be used to refine the sloped shoulder margin?

A

7-8 or #9-10 off-angle hatchet

96
Q

What is the ideal cavosurface angle of the shoulder in a MCC prep?

A

120 degrees

97
Q

What is the ideal width of the shoulder in a MCC prep?

A

1.2 mm

98
Q

What is the ideal facial reduction in a MCC prep?

A

1.5 mm

SP14 - Fixed Restorative (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions