What are the 2 types of bridgework
RR- adhesive held on by palatal wings
Conventional - held on with crowns
Draw an
- Abutment
- Pontic
- Retainers
Draw :P
What is a fixed-fixed bridge?
Retainer - Pontic - retainer
What is a cantilever bridge?
This type of bridge has a retainer at one side of the Pontic only
Advantages of RRB
- Minimal or no preparation
- No anaesthetic needed
- Less costly
- Less surgery time
Disadvantages of RRB (4)
- Debond
- Caries under wing
- Metal shine through
- Chipping porcelain
Indications for RRB
- Young teeth
- Good enamel quality
- Large abutment tooth surface area
- Minimal occlusal load
- Good for single tooth replacement
- Simplify partial denture design
Contraindications for RRB
- Insufficient or poor enamel quality
- Long spans
- Excess soft or hard tissue loss
- Heavy occlusal force e.g. bruxist
- Poorly aligned, tilted or spaced teeth
What do we mount casts on for a bridge?
Mounted on semi-adjustable articulator with facebow registration
When is direct RRB indicated?
- Emergency situations
- If tooth needs XLa immediately
- If tooth has been lost traumatically
Alternative pontics when pts own tooth is not possible
- Acrylic denture tooth
- Polycarbonate crown
- Cellulose matrix filled with composite
Bridge design generally used for anterior region
Cantilever design
Bridge design generally used for posterior region
Fixed-fixed design
Why are cantilevers more successful anteriorly over fixed-fixed?
Avoid fixed in maxilla as divergent guidance paths
Different occlusal forces giong in 2 different directions so more likely for restoration to come off
Anterior cantilever prep if required?
- Occlusal contact reduction
- Cingulum undercut removal
- Chamfer margin 0.5mm supra gingival
Posterior cantilever/fixed-fixed prep if required?
Occlusal rests
180 wrap around with chamfer finish line (0.5mm supra gingival)
+/- Proximal grooves
Materials used for retainer
Cocr or Nickel chromium alloy
Function of sandblasting
Micromechanical retention
Material is used for sandblasting
Aluminium Oxide - 50 microns
Cementing material for bridges (3)
Composite luting cement (PANAVIA)
- Zinc Polycarboxylate cements
- GI
Process of cementing bridge
Dam
Etch
Prime and bond
Cement - no cure
OH adjuncts for pts with bridges
Superfloss
ID brushes
5/10 year survival rate of RRB’s
80%
