Fixed Partial Denture

Question 1

Define the fixed partial denture

Answer 1

A dental bridge that supports artificial tooth on one or both sides of the abutment

Fixed partial dentures are commonly referred to as dental bridges.

Question 2

What are the types of dental bridges?

Answer 2

• Fixed-fixed bridge
• Fixed-movable bridge
• Cantilever bridge
• Spring cantilever bridge
• Maryland or minimum preparation bridge

Each type has unique characteristics and applications.

Question 3

What is a pontic?

Answer 3

The suspended part of the bridge that replaces the missing natural tooth

Pontics are designed to mimic the appearance and function of natural teeth.

Question 4

What is an abutment?

Answer 4

A prepared tooth or an implant retained tooth that supports the bridge

Abutments provide the necessary support for the bridge structure.

Question 5

What is a retainer in the context of dental bridges?

Answer 5

A crown or partial crown that supports the pontic

Retainers are crucial for the stability of the bridge.

Question 6

What is a connector in a dental bridge?

Answer 6

The section that joins the units (retainer and pontic together)

Connectors are essential for the structural integrity of the bridge.

Question 7

What is a pier in a dental bridge?

Answer 7

An intermediate abutment used as a center support in a long span bridge

Piers help distribute the load across the bridge.

Question 8

What defines a Fixed-Fixed Bridge?

Answer 8

• Rigid support
• Strong and retentive
• Can support single or multiple pontics

Requires parallel abutments and lacks independent movement.

Question 9

What are the potential drawbacks of a Fixed-Fixed Bridge?

Answer 9

• Parallel abutments are required
• Lack of independent movement

These drawbacks may lead to complications such as cementation failure.

Question 10

What characterizes a Fixed-Movable Bridge?

Answer 10

• Rigid support & Movable Joint
• Conservative tooth structure
• Suitable for Divergent or Non-parallel abutments

The movable joint allows for small degrees of movement.

Question 11

What are the advantages of a Fixed-Movable Bridge?

Answer 11

• Stress Breaking
• Conservative preparation

This design helps maintain more natural tooth structure.

Question 12

What is a Cantilever Bridge?

Answer 12

Pontic is supported on one side by one or more abutment teeth

It allows for a conservative design that preserves more natural tooth structure.

Question 13

What are the recommendations for using a Cantilever Bridge?

Answer 13

• Use of two abutments
• Limitation to one or two units

Not ideal for long span bridges.

Question 14

What is a Spring Cantilever Bridge?

Answer 14

Pontic is supported by a connecting bar to one or more abutment teeth

This design helps provide stability and support.

Question 15

What are the design rules for a Spring Cantilever Bridge?

Answer 15

• Rigid Bar
• No post dam or bead lines
• Highly polished fitting surface
• 4mm Wide bar
• No contact with gingival tissues

These rules ensure stability, hygiene, and patient comfort.

Question 16

What is a Maryland Bridge?

Answer 16

Retainer wings are luted / cemented on the lingual/palatal surface of the enamel on abutment teeth

This bridge type is less invasive compared to traditional methods.

Question 17

What are the advantages of a Maryland Bridge?

Answer 17

Less invasive, as minimal natural tooth is trimmed away

This approach preserves more of the tooth structure.

Question 18

What are the disadvantages of a Maryland Bridge?

Answer 18

• Debonding can occur
• Not suitable for severe tooth wear or insufficient interocclusal clearance

These factors can limit its effectiveness.

Question 19

What are the advantages of an implant-supported bridge?

Answer 19

• Aesthetic
• May be retrievable
• No tooth preparation
• Preservation of existing bone

Implant-supported bridges offer significant benefits for dental restoration.

Question 20

What are the disadvantages of an implant-supported bridge?

Answer 20

• Prohibitive cost
• Time-consuming clinical and laboratory procedures
• Gingival aesthetics can be difficult

These factors can affect patient decision-making.

Question 21

What dictates pontic design?

Answer 21

• Aesthetic
• Function
• Ease of cleaning
• Patient comfort
• Maintenance of healthy tissue

These factors ensure the pontic serves its purpose effectively.

Question 22

What is the disadvantage of a Saddle or Ridge Lap pontic?

Answer 22

Very difficult to maintain hygiene as they cause tissue inflammation

This design may lead to complications if not properly managed.

Question 23

What is Ante’s Law?

Answer 23

Total root surface area of all the teeth will support a bridge must equal or exceed the total root surface area of teeth being replaced

This law helps ensure adequate support for dental bridges.

Question 24

What is the optimum crown/root ratio for abutment teeth?

Answer 24

1:2

This ratio ensures optimal support for the bridge structure.

Question 25

What factors influence the selection of abutment teeth?

Answer 25

* Ante's Law * Crown : Root ratio * Root Configuration * Periodontal Ligament Area ## Footnote These factors are crucial for the success of the bridge.

Question 26

What are the ideal characteristics of retainers?

Answer 26

* Least bulk * Resist distortion * Minimal tooth substance removal * Self-cleansing or readily cleanable * Aesthetically acceptable ## Footnote These characteristics ensure the effectiveness and comfort of the bridge.

Question 27

Why is the marginal fit critical to the longevity of the restoration?

Answer 27

Cement is soluble in water and eventually breaks down, initiating an incidence of secondary caries ## Footnote A good marginal fit prevents complications over time.

Question 28

What should be considered in the connector design of a dental bridge?

Answer 28

The geometry of the connector cross-section must be large enough to withstand loading ## Footnote Adequate dimensions ensure the structural integrity of the bridge.