Bridgework 2

Question 1

Name all 5 bridge designs with conventional components.

Answer 1

Fixed-fixed
Fixed cantilever
Fixed-moveable
Hybrid (conventional + adhesive retainer)
Spring cantilever

Question 2

Describe the structural arrangement of a fixed-fixed bridge.

Answer 2

Retainer at each end with pontic in middle joined by rigid connectors: (Retainer)-(pontic)-(Retainer)

Question 3

What are all five advantages of conventional fixed-fixed bridges?

Answer 3

Robust design
Maximum retention and strength
Abutment teeth splinted (for perio cases with mobile teeth)
Usable in longer spans
Straightforward laboratory construction

Question 4

List all four disadvantages of conventional fixed-fixed bridges.

Answer 4

Difficult preparation (parallel preps needed)
Must be minimally tapered (5-7°)
Requires common path of insertion
Removal of tooth tissue endangers pulp

Question 5

What two specific problems occur when abutment teeth aren’t parallel?

Answer 5

Preparations not parallel and different longitudinal axes of abutments

Question 6

Describe both retainer options for cantilever bridges and the pontic arrangement

Answer 6

Conventional/crown retainer OR adhesive/resin retained metal wing; pontic connected to one or more retainers at one end only: (Retainer)-(Pontic)

Question 7

What are the three advantages of conventional cantilever bridges?

Answer 7

Conservative design (compared to fixed-fixed)
Straightforward laboratory construction
No need to ensure multiple tooth preparations are parallel

Question 8

State all three disadvantages of conventional cantilever bridges

Answer 8

Short span only
Must be rigid to avoid distortion
Mesial cantilever preferred

Question 9

How does a fixed-moveable bridge solve the non-parallel abutment problem?

Answer 9

Retainers have separate paths of insertion, united by a moveable connector

Question 10

Describe the connector arrangement in a fixed-moveable bridge.

Answer 10

Rigid connector usually at distal end of pontic, moveable connector mesially, allows vertical movement at mesial abutment

Question 11

List all five advantages of conventional fixed-moveable bridges.

Answer 11

No common path of insertion required
Each prep independently retentive
More conservative of tooth tissue
Allows minor tooth movement
May be cemented in two parts

Question 12

What are the four disadvantages of fixed-moveable bridges?

Answer 12

Limited span length
Complicated laboratory construction
Difficulty cleaning beneath moveable joint
Can’t construct provisional bridge

Question 13

Define a hybrid bridge by its retainer types

Answer 13

One retainer = conventional preparation, other retainer = minimal preparation (adhesive/resin retained/resin bonded)

Question 14

Describe the complete structure of a spring cantilever bridge

Answer 14

One pontic attached to end of metal arm running across palate to rigid connector on palatal side of retainer

Question 15

What are the three specific clinical situations favoring spring cantilever bridges?

Answer 15

Spacing between upper incisors
Adjacent teeth unrestored
Posterior tooth suitable as abutment (already has crown/large restoration)

Question 16

List all four disadvantages of spring cantilever bridges.

Answer 16

Only replaces upper incisors
Difficult cleaning beneath palatal connector
May irritate palatal mucosa
Difficult controlling pontic movement (due to arm springiness and palatal tissue displacement)

Question 17

What are the three key requirements for abutment evaluation?

Answer 17

Must withstand forces previously directed to missing teeth
Supporting tissues healthy/inflammation-free (no periapical/periodontal disease)
Adequate crown-to-root ratio

Question 18

What are the optimum and minimum crown-to-root ratios for abutments?

Answer 18

Optimum 2:3, Minimum 1:1

Question 19

Define crown-to-root ratio anatomically.

Answer 19

Length of tooth coronal to alveolar crest compared to length of root embedded in bone

Question 20

Why might epileptic patients specifically benefit from bridgework over removable prostheses?

Answer 20

Fixed prosthesis reduces risk during seizures (removable could become dislodged/aspirated)

Question 21

Why is a 5-7° taper critical for fixed-fixed bridge preparations?

Answer 21

Provides optimal balance between retention (less taper = more retention) and ability to achieve common path of insertion for multiple abutments