Bridgework Flashcards
1
Q
What are our txt options for a missing tooth?
A
- No txt
- Orthodontic
- Replace missing tooth
2
Q
What are some reasons for replacing a missing tooth?
A
- Aesthetics
- Function
- Speech
- Maintenance of dental health (i.e. other tooth)
3
Q
What are some options to replace missing teeth?
A
- Denture
- Bridgework
- Implants
4
Q
What is a bridge?
A
- A prosthesis which replaces a missing tooth or teeth and is attached to one or more natural teeth (or implants)
5
Q
Why might a denture be preferred to a bridge?
A
- When soft tissue needs to replaced or not much bone is there
- Denture can replace these whereas bridge not as much
6
Q
What are some indications for bridgework?
A
- Function and stability
- Appearance
- Speech
- Psychological (may not cope with removable prosthesis
- Systemic disease e.g. epileptics
- Co-operative pt
7
Q
What are some local indications for bridgework?
A
- Big teeth
- Heavily retsored teeth
- Favourable abutment angulations
- Favourable occlusion (not too heavy contact as will come out)
8
Q
What are some contra-indications for bridework?
A
- Uncooperative pt
- Medical history contra-indications (allergy to metal being used)
- Poor oral hygiene
- High caries rate
- Large pulps (young pts likely to become non vital )
- High possibility of further tooth loss within arch
- Prognosis of abutment poor
- Length of span too great (long bridges flex more when pt bites down)
- Ridge form and tissue loss
- Tilting and rotation of teeth
- Degree of restoration (how much tooth is left after prep)
- Periapical status
- Active periodontal disease (bone loss - can’t receive additional occlusal force)
9
Q
What is the definition of abutment?
A
- A tooth which serves as an attachment for a bridge
10
Q
What is the definition of a Pontic?
A
- The artificial tooth which is suspended from the abutment teeth/tooth
11
Q
What is the definition of Retainers?
A
- The extracoronal or intracoronal restorations that are connected to the pontic and cemented to the prepared abutment teeth
12
Q
What is the definition of connectors?
A
- Componet whihc connects the pontic to the retainers/retainer
13
Q
What is the definition of edentulous span?
A
- Space between natural teeth that is to be filled by a bridge or partial denture
14
Q
What is the definition of saddle?
A
- Area of edentulous ridge over which the pontic will lie
15
Q
What is the definition of Pier?
A
- An abutment tooth which stands between and is supporting two pontics, each pontic being attached to a further abutment tooth
16
Q
What is a unit?
A
- Either a retainer or a pontic
- E.g. a bridge with two retainers and one pontic = 3 unit bridge
17
Q
What is a foxed-fixed bridge?
A
- Type of bridge which has a retainer at each end with a pontic in the middle joined by rigid connectors
- e.g. retainer - pontic - retainer
- Can be Conventional or Adheshive/resin retained
18
Q
What is a Cantilever bridge?
A
- Type of bridge which has a retainer (or retainers) at one side of the pontic only
- E.g. retainer - pontic
- Can be conventional or adhesive/resin retained
19
Q
What are Resin Bonded Bridgework (RBB) also known as?
A
- Resin retained bridges
- Adhesive bridgework
- Minimal preparation bridgework
- Maryland bridge
- Resin bonded fixed partial denture
20
Q
What are the two examples of Adhesive cantilever bridges?
A
- All ceramic adhesive bridge
- Traditional adhesive bridge with metal (CoCr) wing
21
Q
What are some advantages of resin bonded bridges?
A
- Minimal or no prep needed
- No anaesthetic needed
- Less costly
- Less surgery time
- Can be used as a provisional restoration (useful if pt child has hypodontia and are wanting a implant later on in life)
- When it fails usually less destructive than alternatives
22
Q
What re some disadvantages of resin bonded bridges?
A
- Rigorous clinical technique (extensive moisture control needed)
- Metal shine through occurs (less aesthetic)
- Porcelain can chip from pontic
- Can de bond (high chance of it debonding again if just re bonded back on)
- May have occlusal interferences (more common with dynamic interference)
- No trial period possible
23
Q
What are some indications of resin bonded bridges?
A
- Young teeth (less destructive)
- Good enamel quality
- Large abutment tooth surface area
- Minimal occlusal load
- Good for single tooth replacement
- Used to simplify partial denture deisgn
24
Q
What some contra-indications of resin bonded bridges?
A
- Insufficient or poor quality enamel
- Long spans
- Excess soft or hard tissue loss
- Heavy occlusal force e.g. bruxist
- Poorly aligned, tilted or spaced teeth
- Contact sports ?
25
Advantages to Direct resin bonded bridgework?
- Very useful in emergency situation
- If tooth needs to be extracted immediately
- If tooth has been lost traumatically
26
Advantages to Indirect resin bonded bridgework?
- No prep needed or minimal needed
27
What is a Direct resin bonded bride?
- Ideally use pt own tooth as a pontic
- Or can use Acrylic 'denture' tooth / Polycarbonate crown / Cellulose matrix filled with composite
- Temp fix, better than pt having a hole / gap in between teeth
28
What is an indirect resin bonded bridge?
- Bridge with metal work on palatal, lingual coverage with 0.5mm supra-gingival left over
- A greater surface of enamel covered therefore a greater bond
29
What design of bride would you choose for Anteriors and Posteriors?
Anteriors - Generally cantilver design
Posteriors - Generally fixed-fixed
30
Why do cantilever bridges generally work better for anterior teeth?
- Divergent guidance path
31
What can you do if there is existing restorations in abutment teeth?
- Ideally need sound enamel
- Composite restoration can be removed and replaced prior to prep so it has a better bond to the bridge
- Amalgam has a compromised bond to chemically cured composite on the bridge, therefore consider replacing with comp
32
What is the preparation technique for RBB if any is needed at all?
- 180degree warp around prep
- Rest seats in posterior (2mm) and cingulum rests in anterior teeth for mechanical retention
- Can use proximal grooves if desired
- Supra-gingival chamfer line approx 0.5mm (more easily cleansable for pt)
- Remain in enamel as better bond than dentine
33
What is the minimal prep if it is needed for cantilever design for anterior?
- Occlusal contact reduction
- Cingulum undercut removal only
- Chamfer margin 0.5mm supra-gingivally
34
What is the Heavier preparation for cantilever design if it is needed for anterior ?
- 0.5mm palatal reduction (metal retainer wing should be 0.7mm thick)
- Cingulum rest cut it
- Proximial grooves
- 0.5mm chamfer margin supra-gingival
35
What should the fit surface of the metal retainer been done before you fit?
- CoCr or Ni-Cr alloy should have been sandblasted by lab
- Increases micro-mechanical retention
- Use Aluminium oxide about 50 microns thick to sandblast
- Improve bond between retoration and tooth
36
What is the process for cementing the bridge?
- Prophylaxis
- Isolate with dental dam
- Etch tooth 37% ortho-phosporic acid
- Wash and dry
- Apply primer for 30 sec
- Air dry 2 sec and don't cure
- Fit retainer coated with luting cement (PANAVIA2 IEX) to abutment tooth/teeth
- Remove Xs cement
- Oxygen inhibitor (oxyguard II) placed around cement margins for 3 mins and wash off
37
What is the 5 year and 10 year survival of RRB?
5 - 80.8%
10 - 80.4%
38
What does conventional in bridge design mean?
- Retainer (s) = crown
39
What are some conventional fixed-fixed bridge advantages?
- Robust design
- Maximum retention and strength
- Abutment teeth splinted together (good for perio cases with mobile teeth)
- Can be used in longer spans
- Lab construction is straightforward
40
What are some conventional fixed-fixed bridge disadvantages?
- Preparation difficult (parallel tooth preps needed)
- Prep must be minimally tapered
- Common path of insertion for abutments which can create issues when abutment teeth are not parallel
- Removal of tooth tissue so danger to pulp
41
What is a cantilever bridge?
- Type of bridge provides support for the pontic at one end only
- Can use conventiona/crown retainer OR adhesive/resin retained with metal wing
- Pontic may be connected to one or more retainers
42
What are some conventional cantilever bridge advantages?
- Conservative design compared to fixed-fixed conventional design
- Lab construction straightforward
- No need to ensure multiple tooth prep are parallel
43
What are some conventional cantilever disadvantages?
- Short span only
- Rigid to avoid distortion
- Mesial cantilever is preferred but not always possible
44
What is a potential solution to the common path of insertion issue in fixed-fixed moveable bridge?
- Reatiners with separate paths of insertion
- Bridge is united by a moveable connector
45
What is a fixed-moveable bridge ?
- Type of bridge has a rigid connector usually at distal end of pontic and moveable connector mesially
- Allows for some vertical movement at the mesial abutment tooth
46
What are some conventional fixed-moveable bridge advantages?
- Preps don't require common path of insertion
- Each preps designed to be retentive independent of others
- More conservative of tooth tissue
- May be cemented in two parts
47
What are the conventional fixed-moveable bridge disadvantages?
- Length of span limited
- Lab construction more complicated
- Possible difficulty in cleaning beneath moveable joint
- Can't construct provsiional bridge
48
What is Hybrid bridge?
- One retainer = conventional prep
- Other retainer with minimal prep (adhesive/resin retained/ resin bonded)
49
What is a spring cantilever bridge?
- One pontic attached to end of metal arm that runs across the palate to a rigid connector on palatal side retainer
50
What are some conventional spring cantilever bridge advantages?
- useful if spacing present between upper incisors
- Where adjacent teeth are unrestored
- Where a posterior tooth would provide a suitable abutment (i.e.e already has a crown/large direct restoration)
51
What are some conventional spring cantilever bridge disadvantages?
- Can only be used to replace upper incisor teeth
- Difficlut to clean beaneth palatal connector
- May irritate palatal mucosa
- Difficult to control movement of pontic, due to springiness of metal arm and displacement of palatal soft tissues
52
What are the important criteria for an abutment evaluation?
- Must be able to withstand forces previously directed to missing teeth
- Supporting tissue healthy and free of inflammation i.e. PA disease and periodontal disease
- Crown to root ratio (length of tooth coronal to alveolar crest compared to length of root embedded in bone - optimum ratio 2:3 , min ratio 1:1
53
