Brainscape's Knowledge GenomeTM

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


See full index

5th year final - all cards combined > Crown and Bridge - All Lectures > Flashcards

Crown and Bridge - All Lectures Flashcards

1
Q

when preparing a tooth for crown prep, what three factors determine how much we prep

A
  1. sufficient tooth reduction for the restorative material
  2. sufficient tooth reduction to achieve physical or chemical retention
  3. preservation of tooth (and pulpal) tissue
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

fixed prostheses can be categorised in to extra-coronal and intra-coronal

what do these two types of prostheses mean?

and what are the types of restoration for each prostheses

A

extra-coronal : refers to the restorations wrapping around the tooth, or is on the outside of the tooth

  1. crowns - full/partial coverage
  2. veneers

intra-coronal : refers to parts of the restorations inside the tooth

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

fixed prostheses can be categorised by the metal that is used.

list 7 of the materials that are used, when making a fixed prostheses

A

metals : include

  1. gold
  2. silver palladium
  3. nickel chrome
  4. ceramic bonded to metal
  1. all ceramic
  2. composites
  3. Acrylic (provisional)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

an extra-coronal restoration has to occupy a three dimensional space bounded by which surfaces of the tooth?

A
  1. proximal surfaces of adjacent teeth
  2. occlusal surfaces of the opposing tooth/teeth
  3. the soft tissues bucally and lingually/palatally
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

an intra-coronal restoration (inlay) has to occupy a three dimensional space bounded by:

A
  1. proximal surface of adjacent teeth
  2. occlusal surface of the opposing tooth/teeth
  3. tooth preparation bucally and lingually/palatally
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

when prepping of tooth tissue, we want to minimally invasive as possible and conserve as much tooth tissue as possible in order to:

  1. protect the pulp
  2. maintain strength in tooth

what will happen if we prepare too much tooth tissue

A
  1. risk of pulpal damage - up to 20% of vital teeth prepared for crowns subsequently need root canal therapy.
  2. risk of losing retention and resistance form
  3. compromised strength of tooth
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

if you do not prepare enough tooth structure for a crown, it will result in a thin material being used for the crown.

what complications can this cause

A
  1. poor aesthetics: tooth surface shining through the ceramic
  2. inadequate strength: each material requires a specific thickness for it to be functional.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

if you do not prepare enough tooth structure for a crown, it will result in a overbuilt crown

what complications can this cause

A
  1. plaque retention: problems with periodonal tissue
  2. poor aesthetics: very bulbous looking
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

the ability of the preparation to prevent dislodgement of a restoration to lateral and oblique forces: is known as what

A

resistance form

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

the ability of the preparation to retain a restoration in an occlusal direction: is known as what

A

retention form

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

chemical retention is achieved when using cement or lute to place the crown.

under what condition is the chemical retention more successful?

what type of preparation causes probelms, when trying to achieve chemical retention?

A

chemical retention is good when loaded in compression. this will be achieved with long tapered crown preps.

short, greatly tapered preparation will result in less compression and result in shearing.

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

the taper of the crown preparation refers to the what

A

90 degree wall preparation, in relation to the long angle of the tooth

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

what does the total occlusal convergence angle refer to

A

it refers to the angle between to opposing walls

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

what would be the purpose of adding this groove to this crown preparation

A

round preparations in particular or more vulnerable to shearing forces. by the addition of grooves it will help with retention.

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

what determines how much tooth tissue is removed and the type of margin is used for a crown prep.

A

the choice of metal being used for the crown prep determines the reduction and margin.

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

metal is very strong in a thin section, what would be the ideal reduction bucally

A

0.5 mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

how much occlusal clearance is needed for a metal crown

A

at least 1mm occlusal clearance

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

what type of margin would be used for a metal crown

A

any finishing margin is accepted (shoulder/chamfer).

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

which of the margins is more conservative and other being more destructive

A

chamfer = conservative

shoulder = destructive

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

a metal ceramic crown has a ceramic, bonded to the metal.

this type of crown will require a compensation in how much tooth structure we prepare.

this type of crown offers a better aesthetic feature compared to a metal crown.

this type of preparation is more destructive - which side of the tooth will be do the prep for the ceramic veener.

A

buccal side.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

for a ceramic metal crown, what would be the required reduction for the buccal surface and the occlusal reduction

A

to accomodate for the additional ceramic material a total reduction of 1.5 mm is required

0.5 mm for the metal and a further 1mm for the ceramic.

for the occlusal reduction 1-2 mm reduction is required.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what type of buccal margin would be used for a metal ceramic crown, bucally and palataly

A

shoulder margin would be required for the metal ceramic (bucally)

chamfer margin for the metal (palataly)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

why is it important for ceramic restorations for the line angles to be smooth and round?

A

to prevent the concentration of stress on any sharp angles.

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

which of these burs is used for : depth groves, shoulder preparation

A

parallel sided, flat ended bur

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

which of these burs is used for : groove/box preparation and shoulder

A

flat ended, tapered

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

which of these burs is used for : occlusal reduction, axial reduction, proximal reduction, chamfer preparation

A

round (chamfer) ended, tapered

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

which of these burs is used for : initial proximal reduction

A

long needle bur

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

which of these burs is used for : lingual/palatal reduction

A

rugby ball

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

which of these burs is used for : refinement of preparation

A

smooth (red band) round ended, tapared bur

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

how must a tapered bur be held to the long axis of the tooth to achieve an ideal taper

A

hold parallel to long axis of tooth

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

what is the diameter of a chamfer bur

A

1 mm

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

where should a finishing margin be?

A
  1. on sound tooth structure
  2. below the contact point
  3. not subgingival
  4. allow for adequate preparation height
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

what kind of reduction must you do on the functional cusp

A

increased reduction on the functional cusp

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

when you are doing the buccal depth cuts, how many planes must you do the depth cuts in?

A

2

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

CROWNS AND CONVENTIONAL BRIDGES - THE CORE TO SUCESS

LECTURE 2

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

what is a core?

A

a core, is a restoration placed in teeth prior to preparation for an indirect restoration

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

what common materials are used to produce a direct core?

A

amalgam

composite

glass ionomer

metal alloy

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

what are the advantages of amalgam as a core material

A
  1. not particularly technique sensitive
  2. strong if placed in sufficient bulk
  3. can be used as a bonded amalagam (dont need to alwasy rely on mechanical retention)
  4. easy to distinguish between amalgam and tooth structure
  5. packable - if condensed well voids are avoided
39
Q

what are the disadvantages of amalgam as a core material

A
  1. long setting time
  2. low initial tensile/compressive strength (core and restoration will be completed in seperate visits)
  3. weak in thin sections
  4. mercury may be concern to some patients
  5. amalgam cannot be used in pregnant and nursing ladies.
40
Q

what are the advanatges of composite resin as a core material?

A
  1. strong and can therefore be placed in thinner sections compared to amalgam
  2. immediate setting with light cured composites allowing immediate preparation
  3. can be bonded to tooth structure
  4. tooth coloured hence ideal under all ceramic crowns
41
Q

what are the disadvantages of composite resin as a core material

A
  1. very technique sensitive - moisture contamination and polymerisation shrinkage should be avoided
  2. can be difficult to distinguish between composite and tooth sttructure when preparing crown margins
42
Q

what are the advantages of GIC and RMGIS as a core material?

A
  1. adhesive
  2. fluoride release
  3. low thermal expansion
43
Q

what are the disadvantages of GIC and RMGIS as core materials

A
  1. low compressive and tensile strengths
  2. deterioration at low pH
  3. sensitivity to moisture during setting - cover in varnish
  4. not packable
44
Q

retention of the core and how retention was gained will depend on what?

A

material used

45
Q

how do we create retention of cores in gengeral - vital teeth

A
  1. undercut preparation
  2. dentine pins
  3. adhesive materials
  4. elective endodontics
    - pulp chamber
    - posts
46
Q

for a successful post

how much gutta percha must be left apically

A

leave 4mm GP apically

47
Q

for a successful post

the diameter of the post apically should not be greater than what measurement

A

diameter of post apically no greater than 1/3rd of root

48
Q

what must be created to fit the corwn on the core buildup

A

a ferrule

49
Q

INDICATIONS FOR CROWNS AND THE PREOPERATIVE ASSESSMENT - LECTURE 3

A
50
Q

what is a crown?

A

a full coverage extra-coronal restoration

51
Q

if a restoration is indirect, what does this mean

A

that the restoration was made eleswhere such as a lab

52
Q

what are the indications for crowns

A
  1. repeated failure of direct plastic restoration
  2. difficulty achieving adequate contour, contact point and occlusal contacts with a direct restoration
  3. minimise risk of tooth fracture
  4. aesthetics
  5. accommodate a metal based removeable prosthesis
  6. bridge abutment
  7. replacement of an existing crown
53
Q

with a direct plastic restoration, if you have inadequate occlusal contatcs, what can that result in

A
  1. increased risk of restoration fracture
  2. subsequent microleakage and secondary caries
54
Q

with a direct plastic restoration, if you have inadequate contact points, what can this lead to

A
  1. contact point not achieved
  2. increased food packing
  3. difficulty cleaning and maintaining restoration
  4. risk of periodontal disease and secondary caries
55
Q

can you restore a cracked crown that has extended to the root?

A

no

56
Q

which of the classification of longitudinal tooth fractures are unrestorable?

A
  1. crown to root extension (cracked tooth)
  2. crown and root; extension to proximal surface (split tooth)
  3. root only (vertical root fracture)
57
Q

encrochment of the biological width occurs how?

A

when the crown is too far subgingival and in the biological width, causing inflammation of the gums and leading to gum recession.

58
Q

Where can ceramics be used in?

A

veneers, crowns and bridges.

59
Q

Which type of material offers potential for highly aesthetic restorations with close approximation to natural tooth tissue?

A

Porcelain (ceramic)

60
Q

What is the disadvantage of all-ceramic restorations?

A
  1. Prone to fracture under oral function
  2. Require larger reductions in tooth tissue compared to metal restorations.
  3. Cost can be high
  4. Reduced scope for adjustment or repair
61
Q

Dental ceramics are classified by 4 different compositions, what are they?

A
  1. Glass based ceramics
  2. Glass infiltrated ceramics
  3. Polycrystalline (non-glass) ceramics
  4. Resin-matrix ceramics
62
Q

What are the three main methods of manufacturing ceramics?

A

Sintering: ceramic powder mixed with water is built to the required shape and exposure to high temperature causing partial melting and fusing of particles.

Hot pressing/injection moulding – similar to the lost-wax technique. A wax up of the restoration is invested in refractory die and a heated block of ceramics is injected under pressure.

Machining – CAD/CAM represents a significant technological advancement with regards to all-ceramic restoration manufacture.

63
Q

Having sharp incisal-occlusal edges on tooth preparations can lead to what?

A
  1. Failure point in the restorative material
  2. Stress concentration at the sharp angle
64
Q

What is wrong with having a gutter preparation?

A

We get a gutter preparation, when trying to create a shoulder margin, whilst using a chamfer bur, instead of a fissure bur.

A gutter preparation would create a lip, this would indicate that too much tooth structure has been removed and would not be suitable for the restorative material.

65
Q
A
66
Q

What are the two types of cuspal coverage restoration?

A

Onlay and Inlay (also ¾ crowns and 7/8 crowns)

67
Q

Why would you use a cuspal coverage restoration?

A

Cuspal coverage restorations are important to preserve the integrity of a weakened tooth against the forces of occlusion.

Cuspal coverage that conduces to less cuspal deflection and better protection of the remaining tooth tissue is recommended for the reinforcement of the tooth.

68
Q

When would you use cuspal coverage restoration?

A

When the integrity of a tooth is compromised and more so if occlusal forces are applied or may be used to correct occlusal discrepancies.

69
Q

What are the tooth preparations for an Au cuspal coverage restoration?

A
  • Non undercut cavity walls
  • Cuspal coverage (1mm) with functional cusp bevel
  • Bevel marginal finish
  • Mini shoulder finish buccally in lower arch
70
Q

Which aspect of the tooth is covered in a ¾ crown?

A

Occlusal, palatal medial and distal, but would not cover the buccal aspect.

71
Q

What is the tooth preparation for a ¾ cuspal coverage restoration?

A
  1. 1mm occlusal reduction
  2. Functional cusp bevel
  3. Chamfer finish on the mesial, palatal, and distal aspect.
  4. Buccal cusp is left untouched
  5. Proximal groves
72
Q

What are the advantages of having a full coverage or intra-coronal restorations?

A
  1. Protects cups (ct intra-coronal)
  2. Reduces sound tooth removal (ct full coverage)
  3. Reduces amount of restorative material required e.g. Au (ct full coverage)
  4. Easier to inspect margins (ct subging. Full coverage)
  5. Potentially better aesthetics buccally (ct full coverage)
73
Q

What are the disadvantages of CT full coverage or only intra-coronal restorations?

A
  1. Complex preparations for clinicians
  2. Complex restorations for technician
  3. Expense (CT intra-coronal)
74
Q

What materials can be used for construction of an indirect restoration?

A
  1. Gold
  2. All ceramic
  3. Composite
75
Q

Can the abutments in conventional bridgework be implants?

A

Abutments can only be natural teeth.

76
Q

the teeth that have been prepared to accept the bridge is known as what?

A

The abutment teeth

77
Q

The parts of the bridgework that fit over the abutment teeth are known as what?

A

Retainer/anchor

78
Q

The part of the bridgework that covers the saddle area is known as what?

A

Pontic

79
Q

The part of the bridge which connects the retainer/anchor to the pontic is known as what?

A

Connector

80
Q

The edentulous space that is going to be replaced by the pontic is called what?

A

Saddle

81
Q

There are four types of bridge what are they?

A
  1. Traditional bridge
  2. Cantilever bridge
  3. Maryland bonded bridge
  4. Implant-support bridge
82
Q

Which type of bridge is this?

A

traditional bridge

83
Q

Which type of bridge is this?

A

cantilever bridge

84
Q

Which type of bridge is this?

A

maryland bonded bridge

85
Q

Which type of bridge is this?

A

implant-supported bridge

86
Q

which of these types of bridges is the most invasive to the least invasive?

  1. Traditional bridge
  2. Cantilever bridge
  3. Maryland bonded bridge
  4. Implant-support bridge
A
  1. Implant-support bridge
  2. Traditional bridge
  3. Cantilever bridge
  4. Maryland bonded bridge
87
Q
A
88
Q

As you move mesial in the mouth in reference to pontic and bridges, what does this decrease on the tooth structure?

A

Loading

89
Q

Why do you tend to cantilever mesially then distally?

A

Occlusal forces are reduced mesially.

90
Q

What do you not want on the pontic once it has been placed in a cantilever design?

A

No loading in inter cuspal position or excursion on pontic.

91
Q

In certain situations when there are tilted abutments what is an ideal type of bridgework to be used?

A

Fixed moveable

92
Q

In a fixed-moveable bridge the seating action must be in favour of a physiological mesial drift, ideally the female component should be sited where to the male component.

A

Ideally female component sited mesial to mesial component.

93
Q

With a conventional fixed bridge, in reference to the tooth prep. If an abutment tooth didn’t share the same straight-line axis as the other abutment tooth. Then what would you risk doing if you tried to create the same straight-line axis on the other tooth?

A

Damaging the pulp.

94
Q
A

5th year final - all cards combined (174 decks)

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