Local indications for BW (3)
- Big teeth
- Heavily restored teeth
- Favourable abutment angulations
General contraindications for BW
- Uncooperative pt
- MH contraindications
- Poor OH
- High caries rate
- Periodontal disease
- Large pulps (conventional BW - may encroach and become non vital)
Indications for a spring cantilever design
Replacing 1 anterior tooth
Advantages of a conventional fixed-fixed bridge
- Robust
- Maximum retention and strength
- Can be used in longer spans
Disadvantages of conventional fixed-fixed bridge
- Prep difficult (parallel tooth prep needed)
- Prep must be minimally tapered
- Common path of I for abutments
- Removal of tooth tissue (encroach pulp)
Advantages of a conventional cantilever bridge
Conservative compared to fixed - fixed
Less prep - dont need multiple tooth preps parallel as only prepping a single crown retainer
Disadvantages of a conventional cantilever bridge
- Short span only
- Rigid to avoid distortion
- Mesial cantilever preferred (abutment more posterior to avoid heavy contact on Pontic)
When can we use a fixed moveable bridge
Problems with abutment teeth not being parallel
Advantages of a conventional fixed-moveable bridge
- Prep doesn’t require a common path of I
- Each prep designed to be retentive independent of others
- More conservative of tooth tissue
- Allows minor tooth movement
Disadvantages of conventional fixed-moveable bridge
- Length of span limited
- Complicated lab contraction
- Difficulty in cleaning beneath moveable
What is a hybrid bridge
One retainer = conventional
Other = minimal prep
Disadv of a conventional spring cantilever
- Can only be used to replace upper incisor teeth
- Difficult to clean beneath palatal connector
- May irritate palatal mucosa
- Difficult to control movement of pontic due to springiness of metal arm and displacement of palatal soft tissues
Optimum crown:root ratio for abutment
2:3
