Brainscape's Knowledge GenomeTM

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


See full index

Clinical Dentistry (all years) > BDS4 Bridges (+adhesive bridges) > Flashcards

BDS4 Bridges (+adhesive bridges) Flashcards

1
Q

Why do we replace missing teeth? (why bother?:))

A
  • Aesthetics
  • Function (chew better, phonate better - tongue in contact with teeth for certain sounds)
  • Speech
  • Maintenance of dental health (overeruption can lead to root exposed - sensitive + caries prone)
    *
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is a bridge?

A

Prosthesis which replaces a missing tooth or teeth and is attached to one or more natural teeth (or implants)

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

What can dentures replace better than a bridge?

A

Soft tissue/bone - bridges can’t achieve this as well so it may not look as good.

Some bridges can replace some gingiva but not a lot

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

What are the 2 most common types of bridgework?

A
  • adhesive bridges
  • conventional bridges
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Difference between adhesive and conventional bridges?

A

Adhesive - held on with wings on the palatal surfaces of teeth (bonded on)

Conventional - held on by crowns on either side

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

What are the general indications for bridgework?

A
  • for function and stability
  • appearance
  • for speech
  • for psychological reasons (pt reluctant for removable prosthesis)
  • systemic diseases (epileptics - risk of inhaling/choking on a small denture)
  • co-operative pt (to reduce failure risk)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the local indications for bridgework?

A
  • big teeth (more surface area)
  • heavily restored teeth (for conventional bridges - crowns)
  • Favourable abutment angulations
  • Favourable occlusion (dont have heavy occlusal contacts on bridgework - more likely to fail)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are some general contra-indications for bridgework?

A
  • uncooperaitve pt
  • med hx contra-indications (allergy to certain metals used)
  • poor OH
  • high caries rate
  • active perio
  • Large pulps (conventional - need RCT in future as will loose vitality. tends to be younger pts)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are some local contra-indications for bridgework?

A
  • high possibility of further tooth loss within arch soon (denture better)
  • poor prognosis of abutment tooth
  • length of span too great (more than 1 or 2 teeth)
  • Ridge form and tissue loss
  • Tilting and rotation of teeth
  • Degree of restoration (how much tooth is left after prep?)
  • Periapical status (active endo or pulpal disease)
  • Perio status (bone loss) - poor alveolar bone support = not good for the bone to be recieving extra occlusal forces as an abutment tooth
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Why is the span of the bridge importnat? (why is a large span undesireable?)

A
  • the more teeth replaced then the greater the flex of the bridge
  • there will be more force on the bru=idge
  • more prone to fracture
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What needs to be considered about the ridge form and tissue loss for bridgework? / Why might it be a contra-indication?

A
  • Dont get tissue/gingival replacement from a bridge (except a vsmall amount)
  • Ridge form -the missing tooth is not the only aesthetic problem. Its also the gingival archietecture surrounding the tooth to give a natural appearance. so if you have a flat ridge trying to replicate the arch shape of gingival contouring it is difficult when just replacing a tooth
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are abutment teeth?

A

Tooth/teeth which serve as an attachment for bridge (one at the side)

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

What are pontic teeth?

A

The artificial tooth/teeth which is suspended from the abutment teeth/tooth

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

What are the retainers?

A

The extracoronal or intracoronal restorations that are connected to the pontic and cemented to the prepared abutment teeth

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

What are the connectors?

A

The component which connects the pontic to the retainer/retainer

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

What is the edentulous span?

A

The space between natural teeth that is to be filled by a bridge or partial denture

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

What is a pier?

A

An abutment tooth which stands between and is supporting two pontics, each pontic being attached to a further abutment tooth

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

What is a unit and how is it used to describe bridges?

A

a unit is either a retainer or a pontic

e.g. a bridge with two retainers and one pontic = 3 unit bridge

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

What are the main bridge designs? (not the type - conventional/adhesive)

A

fixed-fixed (retainer at each side with pontic in middle)

cantilever (retainer or retainers at one side of the pontic only)

Both can be convential or adhesive bridges

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

With an adhesive cantilever bridge, what is the metal commonly used for the metal retainer wing?

A

CoCr

22
Q

What are the advanatges or resin-bonded/adhesive bridges?

A
  • minimal or no prep
  • no LA needed
  • less costly
  • less surgery time
  • can be used as a provisional resoration (until implants etc)
  • if it fails it is usually less destructive than alternatives
23
Q

What are the disadv of resin bonded/adhesive bridges?

A
  • rigorous clinical technique (if contaminated with saliva won’t last long)
  • may get metal shine thru on incisors with wear
  • chipping pocelain
  • can debond (if debonds once then high chance of it debonding again)
  • No trial period possible (can only really use definitve cements to set them in)
24
Q

What are the indications for using a resin bonded/adhesive bridge?

A
  • young teeth (less destructive)
  • good enamel quality (as bonding to enamel)
  • large abutment tooth surface area (the more surface area - more bonding area so more retentive)
  • minimal occlusal load
  • good for single tooth replacement
  • can simplify a partial denture design
25
Q

What are contra-indications of adhesive bridges?

A
  • insufficient or poor quality enamel
  • long spans (more likely to flex in the middle and fracture)
  • excess soft or hard tissue loss
  • heavy occlusla force e.g. bruxist
  • poorly aligned, tilted or spcaed teeth
  • Contact sports ?? (possibly but would provide mouthguard)
26
Q

In tx planning for bridges what are you looking for in the pt hx?

A

Establish habits - bruxism

27
Q

What should you be looking at when doing an exam in a possible candidate for bridgework?

A
  • Dynamic occlusal relationships (protrusion, lateral excursions)
  • Periodontal health
  • radiological views
  • abutment teeth
  • aesthetics (ginigval contour)
28
Q

You use study models for bridgework. How should they be mounted/on what?

A

Mounted on a semi-adjustable articulator with facebow registration

Note: can also do diagnostic wax ups for an idication of what the final aesthetic result will be

29
Q

What pt/behavioural habits do you need to consider for bridgework?

A

Will the pt be able to maintain the complex work - need good OH

30
Q

When is direct resin bonded good for?

A
  • the emergency situation
    e. g. tooth needs to be extracted immediately or the tooth has been lost traumatically
31
Q

What is direct bonded toothwork?

A

e. g. tooth extracted
- root is cut off and pulpal tissue removed from pulp chamber
- contact points etches and composite fills hole to pulp chamber
- prime and bond etched surfaces
- basically split the tooth to the natural teeth using composite

32
Q

What are the options for manufacturing the pontic (fake) tooth?

A
  • ideally would use pt’s own tooth
  • acrylic denture tooth
  • polycarbonate crown
  • cellulose matrix filled with composite
33
Q
A
34
Q

For indirect resin bonded bridges, what is the ideal palatal/lingual coverage of the abutment tooth?

A

Need geberous palatal/lingual coverage as the greater the surface area of enamel covered, the greater the bond

35
Q

With regards to enamel and proximity to the gingival margin, what is desireable for resin bonded bridgework?

A
  • need good quality enamel to bond to
  • keep work supra-gingival (ideal = 0.5mm)
36
Q

Why do you need to be careful with palatal/lingual coverage of teeth near the incisal edge for resin bonded bridgework?

A

-because the enamel is more translucent near the incisal edge of anterior teeth and will get a grey shine-through from the metal back

37
Q

When would you use a cantilever vs fixed-fixed resin bonded bridge design in the mouth?

A

Anterior = generally cantilever

Posterior = generally fixed-fixed

38
Q

Why are cantilever bridges used/are more successful anteriorly?

A

The occlusal forces are directed down the anterior teeth ina different way/direction (shown by red lines)

The restoration will therefore get jutted around a lot because the forces on the abutment teeth are going in opposite directions

This means the bridge is more likely to fail

Note: may debond on one tooth and get ingress and caries

39
Q

What would you do if there were exisiting restorations in the abutment teeth?

A

Ideally want sound enamel but:

  • Composite = ok but might want to replace prior to bridge prep as you get a better bond to newer composite
  • Amalgam - compromised bond to the chemically cured composite cement so consider replacing
40
Q

If required what prep would you do to an anterior tooth (minimal prep)?

A

Cantilever design (want no prep if possible)

Minimal prep:

  • occlusal contact reduction
  • cingulum undercut removal only
  • chamfer margin (0.5mm supra-gingival)
41
Q

Why is the chamfer margin only 0.5mm when the thickness of the metal wing for an adhesive bridge is 0.7mm?

A

Because the .2mm will settle within 2 weeks (occlusal changes etc)

42
Q

What is the heavier prep that can be done to anterior teeth for adhesive bridges?

A
  • 0.5mm palatal reduction
  • cingulum rest seat
  • +/- proximal grooces
  • chamfure margin 0.5mm
43
Q

What posterior prep can be done for bridges?

A
  • occlusal rests
  • 180 wrap-around with chamfur finish line (0.5mm supra-gingival)
  • +/- proximal grooves
  • can be cantilever or fixed-fixed
44
Q

What are options for temporisation?

A
  • Consider an RPD
  • If the prep remains in enamel there’s not really a need for temporisation
  • If prep goes into dentine and is sensitive then cover with a layer of dentine bonding agent
  • Fit the bridge as quickly as possible to minimise over-eruption and tooth movement
45
Q

What is done to the fit sufrace of the metal retainer wing to help improve the bond? What kind of retention does this provide?

A

The surface is sandblasted (its like etching)

Aluminium oxide is fired at the fitting surface

Gives micro-mechanicala retention

46
Q

What do you do to the retianer of the adhesive bridge (metal wing) before cementing it in?

A
  • try it in for fit and aesthetics
  • chairside micro-etching with aluminium oxide if not already done by the lab
  • clean retainer if contaminated by unset comp resin used to try-in bridge (can use ultrasonic if required)
  • Apply chemically cure (or dual cure) composite luting cement just prior to placement of restoration after tooth treatment is complete
47
Q

What tooth prep is done before fitting the metal retainer (wing) of an adhesive bridge?

A
  • prophylaxis (scaling of tooth?)
  • isolate with dental dam
  • etch tooth (37% phosphoric acid)
  • Wash and dry
  • apply primer (A and B mixed together) for 30secs
  • air dry for 2 seconds
  • no need to cure
48
Q

When actually cementing the bridge into the mouth, what is done?

A
  • chemical or dual cured comp luting cement on retainer
  • fit retainer to abutment tooth
  • remove excess cement
  • Oxygen inhibitor (Oxyguard II) placed around cement margins for 3 mins then washed off
49
Q

Post-cementation, what do you want to do?

A
  • check there is no heacy occlusal contacts on the pontic (fine if on wings)
  • demonstrate cleaning around and underneath the bridge (superfloss and interdental brushes)
50
Q

What are the survuval rates for resin-bonded (adhesive bridges)?

A

5-year = 80%

10yr = 80%

Clinical Dentistry (all years) (5 decks)

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