RR types of design
Cantilever
Fixed-fixed
Conventional types of designs
Cantilever
Fixed-fixed
Fixed-moveable
Types of pontic
- Wash through
- Dome
- Ovate
- Modified ridge lap
- Ridge lap
Function of a pontic tooth
Restores appearance of missing tooth
Stabilise the occlusion
Improve masticatory function
List 3 main considerations for pontic design
- Cleansability
- Smooth
- Surface should not harbour join of metal and porcelain
- Embrasure space smooth and cleanable - Appearance
- Anteriorly as tooth like as possible - Strength
- Longer the span, greater the thickness required to withstand occlusal forces
Features of a wash through pontic
Makes no contact with soft tissue
- Functional > appearance
- Consider in lower molars
Features of a dome-shaped pontic
Useful in lower incisor, premolar or upper molar areas
Acceptable if occlusal 2/3 of buccal surface visible
Features of a modified ridge lap pontic
- Buccal surface as much like tooth as possible
- Lingual surface cut away
- Prob less with food packing on lingual surface of ridge
Features of a ridge lap/saddle pontic
- Greatest contact with soft tissue
- Less food packing than ridge lap
- Can cause blanching of soft tissue
Materials for conventional bridges
- All metal
(gold, nickel/cocr, SS) - Metal ceramic
- All ceramic
(cement with Zirconia, lithium disilicate) - Ceromeric
Clinical steps to conventional BW
- Mounted study models + consider diagnostic wax up
- Request lab to construct vacuum formed stent
(Allows checking of reduction during tooth prep + provisional bridge) - Select shade
- Occlusal or incisal reduction
- Separation of teeth
- Aim for parallelism of tapered surface of each prep
- Construct provisional bridge + cement
- Write prescription
What does parallelism mean?
Single path of I
No undercuts
What must be included in a BW prescription?
Abutment teeth
Pontic + shape
Materials
Materials to cement metal conventional/ MC bridgework
GI luting cement (Aquacem)
RMGI luting cement (Relyx)
Materials to cement RRB (all types)
Anaerobic duel cure resin cement with 10-MDP (Panavia)
Material to cement all ceramic bridge
Dual cure resin cement (NEXUS)
Why do you avoid distal cantilevers?
Concern if occlusal forces on pontic will tilt abutment tooth
When may you consider a distal cantilever?
Premolar abutment if unopposed or opposed by a denture
