Bridgework Flashcards
What is the definition of a bridge?
A prosthesis which replaces a missing tooth or teeth and is attached to one or more natural teeth or implants
What are bridges used for?
To replace missing teeth
What are alternatives to bridges? (4)
no treatment, implants, close space with orthodontics or RPD
Why should we replace teeth? (3)
- Improve aesthetics
- Function– mastication and speech
- Maintaining dental health of other teeth – i.e. tilting of adjacent teeth and overeruption of opposing teeth
If a patient needs a tooth replaced and has a greater loss of soft tissue and bone, what is the best treatment option?
RPD - can restore gingival contours
List the types of bridge designs (7)
Adhesive
- cantilever
- fixed-fixed
Conventional
- cantilever
- fixed-fixed
- fixed movable
- hybrid
- spring cantilever
What is an adhesive bridge?
Where the Pontic is held by wing retainer(s) on abutment teeth
1 wing = cantilever
2 wings = fixed fixed
What is a conventional bridge?
Where the Pontic is held by a crown retainer(s) on abutment teeth
1 = cantilever
2 = fixed fixed
(can have other designs)
What are patient indicators for using a bridge (adhesive or conventional) (6)
- Improve aesthetics
- Improve function & stability
- Improve speech
- Psychological reasons
- Systemic disease e.g. epileptic – inhaled removable dentures so need something fixed
- Cooperative patient with good OH, no active disease and motivated
What are local indicators for using a bridge (adhesive or conventional) (4)
- Large teeth – increases surface area
- Heavily restored – already compromised so ideal esp for conventional
- Favourable abutment angulations
- Favourable occlusion with no heavy contacts on the bridge
What are patient contraindications for using a bridge (adhesive or conventional) (5)
- Poor cooperation
- Poor OH with active disease (caries and perio)
- Unmotivated
- Medical history – allergies to materials
- Age – esp for conventional bridges, young patients with large pulps
What are local contraindications for using a bridge (adhesive or conventional) (8)
- High chance or further tooth loss – better with denture
- Poor prognosis of abutment teeth
- Length of the space that requires filled (the fewer the teeth being replaced the better, longer bridges flex more under load)
- Lack of ridge form and tissue form – Denture better at replacing this
- Tilting and rotation of teeth – can make it difficult to seat the bridge and adjust occlusion
- Degree of restoration on the teeth
- PA status – cannot use teeth with active disease as abutment
- Active/advanced perio = poor abutment
Define an abutment.
A tooth which serves an attachment for a bridge
Define a pontic.
The artificial tooth suspended from the abutment teeth
Define a retainer.
The extra-oral/intra-oral restoration that is connected to the Pontic and cemented to the prepared abutment teeth.
Define a connector.
The component which connects the Pontic to the retainer
Define a pier.
An abutment tooth which stands between and is supporting 2 poetics being attached to further abutment teeth.
Define a unit.
Can be a retainer or Pontic
e.g. a bridge with 2 retainers and 1 Pontic = 3 unit
Define a saddle.
An area of edentulous ridge over which the Pontic will lie.
What is a fixed fixed bridge design?
A bridge where there are retainers on either side of the pontic(s)
- can be conventional or adhesive
Where are fixed-fixed designs commonly used in the arch?
Commonly used posteriorly
Why are fixed-fixed designs not commonly used anteriorly and why are cantilevers more commonly used?
- Anterior teeth in the maxilla have divergent guidance paths
- have different longitudinal axis
- as a result the occlusal forces are directed down the teeth in different ways
- don’t want to cement these teeth together (fixed-fixed) as it can cause “jutting” of the bridge (since the pontic is attached to 2 teeth with occlusal forces going in 2 different directions)
= cause it to fail and debond.
What is a cantilever bridge design?
Where there is a retainer on one side of the pontic only
- can be conventional or adhesive
Where are cantilever designs commonly used in the arch?
anteriorly
What materials can the wings of adhesive bridges be made from? (3)
Metal - CoCr or NiCr
all ceramic
What are the advantages of adhesive bridges? (6)
- Minimal or no tooth preparation
- No LA – since no/little preparations
- Less costly
- Less time in the chair
- Can be used as Provisionals i.e. hypodontia patients to replace teeth before implants
- If bridge fails – no tooth tissue destroyed (compared to crowning etc)
What are the disadvantages of adhesive bridges? (6)
- Must have good technique e.g. needs tooth to be dry for cementing etc
- Metal shine through (i.e. along incisa edge) – from poor design or cementing or very translucent incisal edges
- Porcelain of pontic can chip off
- Can debond – recementing = will never have as good a bond as the first time = more likely to fail
- Occlusal interferences – less common in static occlusion these days due to axial tooth movements (DAHL) can be more problematic during dynamic (lateral) movements
- No trial period possible – can only use definitive cements no temps
What are the Indications for adhesive bridges? (6)
- Younger teeth – less destructive and won’t interfere with the pulp
- Good enamel quality – since bonding to enamel with resin-based cements
- Large abutment tooth surface area
- Use in sites with minimal occlusal load
- Good for single tooth replacement
- Simplify RPD design
What are the contraindications for adhesive bridges? (6)
- Poor quality of enamel
- Longer spans of teeth needing replaces
- Excess soft tissue and hard tissue loss
- Heavy occlusal forces e.g. bruxism
- Poorly aligned, tilted or spaced teeth – problems with path of insertion and aesthetics
- Potentially problematic with contact sports – not a complete Contra-indication, ensure mouthgaurds.
What are the types of adhesive bridges (not designs) and when are they used? (2)
- Direct
- Useful for emergency i.e. after extraction after trauma as they are done chairside on the day - Indirect - standard type that requires lab prep and 2 appointments
How do we construct a DIRECT adhesive bridge after trauma? (2 ways)
- Use patients own tooth as the pontic
- Alternatives if tooth lost: use acrylic denture tooth, prefabricated polycarbonate crowns or cellulose matrix of tooth shape filed with composite
Describe in detail the process of providing a direct adhesive bridge. (6 steps)
- Cut root off of extracted tooth
- Remove pulp in crown
- Place composite over the pump chamber
- Etch the contacts of the tooth and the “abutment teeth” contacts
- Reseat the tooth
- Composite between contacts on both sides and cure in place