Bridgework 3

Question 1

RR types of design

Answer 1

Cantilever
Fixed-fixed

Question 2

Conventional types of designs

Answer 2

Cantilever
Fixed-fixed
Fixed-moveable

Question 3

Types of pontic

Answer 3

• Wash through
• Dome
• Ovate
• Modified ridge lap
• Ridge lap

Question 4

Function of a pontic tooth

Answer 4

Restores appearance of missing tooth
Stabilise the occlusion
Improve masticatory function

Question 5

List 3 main considerations for pontic design

Answer 5

1. Cleansability
   - Smooth
   - Surface should not harbour join of metal and porcelain
   - Embrasure space smooth and cleanable
2. Appearance
   - Anteriorly as tooth like as possible
3. Strength
   - Longer the span, greater the thickness required to withstand occlusal forces

Question 6

Features of a wash through pontic

Answer 6

Makes no contact with soft tissue
- Functional > appearance
- Consider in lower molars

Question 7

Features of a dome-shaped pontic

Answer 7

Useful in lower incisor, premolar or upper molar areas
Acceptable if occlusal 2/3 of buccal surface visible

Question 8

Features of a modified ridge lap pontic

Answer 8

• Buccal surface as much like tooth as possible
• Lingual surface cut away
• Prob less with food packing on lingual surface of ridge

Question 9

Features of a ridge lap/saddle pontic

Answer 9

• Greatest contact with soft tissue
• Less food packing than ridge lap
• Can cause blanching of soft tissue

Question 10

Materials for conventional bridges

Answer 10

• All metal
  (gold, nickel/cocr, SS)
• Metal ceramic
• All ceramic
  (cement with Zirconia, lithium disilicate)
• Ceromeric

Question 11

Clinical steps to conventional BW

Answer 11

1. Mounted study models + consider diagnostic wax up
2. Request lab to construct vacuum formed stent
   (Allows checking of reduction during tooth prep + provisional bridge)
3. Select shade
4. Occlusal or incisal reduction
5. Separation of teeth
6. Aim for parallelism of tapered surface of each prep
7. Construct provisional bridge + cement
8. Write prescription

Question 12

What does parallelism mean?

Answer 12

Single path of I
No undercuts

Question 13

What must be included in a BW prescription?

Answer 13

Abutment teeth
Pontic + shape
Materials

Question 14

Materials to cement metal conventional/ MC bridgework

Answer 14

GI luting cement (Aquacem)
RMGI luting cement (Relyx)

Question 15

Materials to cement RRB (all types)

Answer 15

Anaerobic duel cure resin cement with 10-MDP (Panavia)

Question 16

Material to cement all ceramic bridge

Answer 16

Dual cure resin cement (NEXUS)

Question 17

Why do you avoid distal cantilevers?

Answer 17

Concern if occlusal forces on pontic will tilt abutment tooth

Question 18

When may you consider a distal cantilever?

Answer 18

Premolar abutment if unopposed or opposed by a denture