Brainscape's Knowledge GenomeTM

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


See full index

CSAR > CSAR 33, 34, 35 - Bridges > Flashcards

CSAR 33, 34, 35 - Bridges Flashcards

1
Q

What do you need to know about abutment teeth before any prep?

A

Angulation
Vitality
Crown-root ratio

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

When are articulated study models needed before tooth preparations?

A

Long bridge spans
Multiple extracoronal restorations
Reorganising occlusion

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

Why are bridges used?

A 
Aid chewing and speech 
Distribute forces
Prevent drift 
Aesthetic 
Maintain face shape
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the retainer of the bridge?

A

Restoration that attaches the bridge to the abutment tooth/teeth

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

What do conventional bridges rely on when placed? And what 3 types are there?

A

Rely on crown principles for retention
Cantilever
Fixed-fixed
Fixed-moveable

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

How are RBB attached to tooth prep?

A

Resin-based cements for adhesion

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

What are advantages and disadvantages of conventional bridges?

A

+ Abutments may already be heavily restored
+ Can alter shape and colour of teeth
+ Retention better if crown principles applied correctly
+ Last longer than adhesive bridges

  • Use crowns as retainers is very destructive
  • Impression-taking more difficult = silicone used which is hydrophobic
  • Longer preparation time
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What shape are the tooth preparations of fixed-fixed bridges?

A

PARALLEL

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

What is the advantage of using a fixed-moveable bridge over a fixed-fixed bridge?

A

Has a stress breaker

Teeth don’t need to be parallel

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

What are the connections on a fixed-moveable bridge?

A

One side rigid support

Other side intra/extra-coronal attachments and small degree of movement

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

What movements are allowed and resisted by a fixed-moveable bridge?

A

Small amount of vertical movement

Resists lateral movement

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

What are advantages and disadvantages of adhesive bridges?

A

+ Preservation of sound tooth tissue
+ Little preparation
+ Impression taking very much easier

  • Don’t last as long
  • Cannot change shape of abutment teeth
  • Can discolour abutments if they are thin
  • Heavily restored abutments not ideal – need ENAMEL!
  • Shine through of wing
  • Hard to try-in
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the difference between minor and major bridge retainers?

A

Major need full occlusal coverage and minor don’t

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

When planning for a bridge, what do you want to know about the edentulous ridge?

A
  • Ridge shape (pontic selection)
  • Alveolar bone loss (disguise or augment)
  • Retained roots
  • Unerupted teeth = need to let patient know that they are there and document it
  • Lip line
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

When are conventional bridges more suitable than adhesive?

A

Heavily restored teeth when can not be bonded to enamel
Long spans
Repeated failure of adhesive bridges
Implants not possible

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

What is Ante’s law when treatment planning dentures?

A

THE TOTAL PERIODONTAL MEMBRANE AREA OF THE ABUTMENT TEETH MUST EQUAL OR EXCEED THAT OF THE TEETH TO BE REPLACED

17
Q

When using an abutment tooth that has had endo, what should be known of the tooth?

A

The endo must be good, or redo it

18
Q

What abutment teeth are preferred due to their root shape and angulation?

A
  • Molars with divergent roots offer more support than those with straight conical roots
  • Single rooted teeth with elliptic cross sections offer more support than those with a circular cross section
19
Q

What is the optimum crown-root ratio and why?

A

Optimum crown-root ratio 2:3
Large root – coronal part may break
Small root – root may break
Official minimum is 1:1 = IF OPPOSED BY DENTURE

20
Q

What happens to forces on a bridge with a longer span?

A

Increases load on abutment teeth

Less rigid and increased flexing, resulting in fractures/debonding

21
Q

If there are small defects in the alveolar ridge due to bone loss when placing a bridge, what can be done to correct this?

A

Add pink porcelain

22
Q

Why should a bridge with double abutments be avoided?

A

Central abutment acts as a fulcrum causing debonding of the peripheral retainer

23
Q

What are advantages and disadvantages of fixed-fixed bridges?

A

+ Robust with maximum retention and resistance
+ Recommended for larger bridges

  • Parallel preps = DIFFICULT
  • Destructive
  • Cementation is difficult
24
Q

What are advantages and disadvantages of fixed-moveable bridges?

A

+ Preps do not need to be parallel
+ More conservative as prep for minor retainer less than major
+ Allows minor movements of teeth
+ Parts can be cemented separately

  • Length of span limited
  • Complex laboratory process
  • Temporisation is difficult
  • More expensive
25
Q

What are advantages and disadvantages of cantilever bridges?

A

+ Most conservative easier prep
+ Anterior region where occlusion is favourable

  • Limited to one pontic
  • Rigid construction
  • Occlusal forces can encourage tilting posteriorly if the pontic is distally positioned
  • Occlusal forces can encourage rotation of abutment anteriorly if care not taken with occlusion
26
Q

Why would a bridge fail?

A

One abutment loosens
Debond and fall out
Fracture

27
Q

Why would an abutment fail?

A 
Loss of vitality
Endo failure 
Caries 
Periodontal disease
Fracture of natural crown
28
Q

After prepping a tooth for a RBB and not putting a temporary over it, what might the patient complain of?

A

Sensitivity

29
Q

After prepping a tooth for a RBB why mustn’t fluoride varnish be placed on after?

A

Fluoride ion integrates with hydroxyapatite and changes the surface, affecting bonding

30
Q

If can not get Pontic tooth out of guidance, what type of guidance is referred?

A

Group function

31
Q

When doing a preparation for a RBB what should you do to ensure bonding success?

A

Have 180 degrees wraparound
Occlusal coverage posteriorly to increase surface area for bonding and reduce sheer stress
Minimum thickness of 0.7mm to reduce flexing

32
Q

What type of margin is created with a RBB?

A

Chamfer margin, to help with seating the wing

33
Q

Before bonding of RBB, what steps can aid success of bonding

A 
Sandblast metal with alumina 
Silicate coating 
Tin plating 
Primer added 
Enamel surface etch
34
Q

Why may a cingulum rest help adhesive with a RBB?

A

Resists sheer stress and acts as a locating device

35
Q

How may you ensure you have adequate crown height for a bridge preparation?

A

Possible crown lengthening using electrocautery

36
Q

When using a metal wing on a RBB, what cement would be best?

A

To stop grey shine through use an opaque cement

37
Q

What is the process when cementing a RBB with panavia?

A
  • Clean abutment
  • Etch for 10s, rinse and dry
  • Apply ED Primer II to entire abutment surface, leave for 30s, then dry
  • Apply the mixed panavia paste to the wing
  • Firmly seat the retainer and maintain finger pressure for 60s
  • While maintaining finger pressure remove all excess with a microbrush/probe
  • Light cure for 20s or Oxyguard and leave for 3 min then rinse off Oxyguard
  • Remove any excess
38
Q

Why would bond failure occur in a bridge? and how is this overcome?

A
  • Inadequate moisture control
  • Inadequate seating resulting in uneven cement layer
  • Inadequate surface treatment of fit surface
  • Cement out of date/ instructions not followed

What to do if it is a bond failure
• Remove all existing cement
• Sand blast
• Rebond

39
Q

What is the bucket handle effect of anterior bridges?

A

Curve involved when placing Pontic teeth in their natural position, not straight line
Tilting forces on abutment teeth are greater

CSAR (12 decks)

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