Bridgework 3

Question 1

What occlusal information should you take into account during bridge design?

Answer 1

• Incisal classification (ortho lectures)
• Canine-guided or group function?
• Opposing tooth over-erupted?
• Will bridge interfere with current occlusion?
• Signs of parafunction present?

Question 2

What is the function of the pontic?

Answer 2

• Restore appearance of missing tooth
• Stabilise the occlusion
• Improve masticatory function

Question 3

What are the different ridge surface designs?

Answer 3

Wash through (hygienic or sanitary)
Dome- Shaped (torpedo or bullet shaped)
Modified ridge lap
Ridge lap/Saddle
Ovate

Question 4

Features of Wash Through

Answer 4

• Makes no contact with soft tissue
• Functional rather than for appearance
• Consider in lower molar area

Question 5

Features of Dome-Shaped

Answer 5

• Useful in lower incisor, premolar or upper molar areas
• Acceptable if occlusal 2/3 of buccal surface visible
• Poor aesthetics if gingival 1/3 of tooth visible

Question 6

Features of Modified Ridge Lap

Answer 6

• Buccal surface looks as much like
  tooth as possible
• Lingual surface cut away
• Line contact with buccal of ridge
• Problems with food packing on lingual surface of ridge

Question 7

Features of Ridge Surface

Answer 7

• Greatest contact with soft tissue
• If designed carefully: can be cleansed
• Care taken not to displace soft tissue or cause blanching of tissue

Question 8

Features of Ovate

Answer 8

• Can give excellent aesthetics (mimics tooth emergence from gingivae)
• More difficult to clean
• Difficulty in fully seating bridge if poorly designed and/or constructed

Question 9

Features of LAVA 3M ESPE

Answer 9

 3 – 4 unit fixed bridge (Maximum span) milled zirconium oxide frame with feldspathic porcelain overlying
 Withstand occlusal forces
 Good aesthetics
 Similar reduction to MCC

Question 10

How are conventional bridges prepped?

Answer 10

 Mounted study models
 Consider diagnostic wax-up and custom impression tray
 Request laboratory to construct vacuum-formed stent - allows checking of reduction during tooth preparation, allows construction of provisional bridge
 Select shade
 Laboratory made stent or make pre-operative putty
impression for provisional bridge
 Occlusal or incisal reduction
 Separation of teeth
 Aim for parallelism of tapered surface of each preparation

Question 11

When would you use parallelism?

Answer 11

Consider for fixed-fixed conventional bridge
 Requires two or more teeth to be prepared in a manner to provide a
common path of insertion – increased retention
 No undercuts

Question 12

What are the different cement systems for different materials?

Answer 12

 All metal conventional bridgework
- Aquacem (GI luting cement)
- RelyX

 Adhesive/resin-bonded/resin-retained bridgework
- Panavia 21 (anaerobic duel cure resin cement with 10-MDP)- (all material types)
- RelyX Unicem – All ceramic
- NEXUS® kit (duel cure resin cement) (all ceramic)

 All ceramic conventional
- NEXUS® kit (duel cure resin cement)
- RelyX Unicem – All ceramic

Question 13

Why are distal cantilevers avoided?

Answer 13

Concern that occlusal forces on pontic will produce leverage forces on abutment tooth causing it to tilt/debond

May consider distal cantilever from premolar abutment if unopposed or opposed by a denture