Fixed Bridges

Question 1

define fixed dental prosthesis

Answer 1

“Any dental prosthesis that is luted, screwed or mechanically attached to natural teeth, tooth roots, and/or dental implant abutments providing the primary support for the dental prosthesis”

Question 2

What are the components of a fixed dental prosthesis?

Answer 2

Abutments, pontics, and retainers.

Question 3

What are abutments?

Answer 3

Teeth or implants that directly receive pressure from the prosthesis.

Question 4

what is the retainer?

Answer 4

Question 5

what is an abutment?

Answer 5

Abutment: That part of a structure that directly receives the pressure, the abutments can either be natural teeth or abutment component in a dental implant.

Question 6

what are the 2 types of abutments?

Answer 6

Question 7

What is a pontic?

Answer 7

Pontic: An artificial tooth on a fixed dental prosthesis that replaces a missing natural tooth, restores its function, and usually fills the space previously occupied by the clinical crown

Question 8

What are the types of pontic designs?

Answer 8

Modified ridge lap, sanitary, and ovate.

Question 9

What is a modified ridge lap pontic?

Answer 9

A pontic design that is the most common type.

contact with ridge buccaly

Question 10

What is an ovate pontic?

Answer 10

A pontic design requiring soft tissue surgery, mostly used for anterior teeth.

Question 11

What is a sanitary pontic?

Answer 11

A pontic design that allows space for cleaning underneath.

no contact with ridge at all

Question 12

What is the purpose of retainers in a prosthesis?

Answer 12

To cement the bridge to the abutments.

Question 13

What forms can retainers take?

Answer 13

Full crown, ¾ crown, inlay/onlay, or metal wing.

Question 14

What is a conventional fixed-fixed bridge?

Answer 14

A fixed prosthesis where the pontic is supported by two abutments, one on each side.

conventional prep of abutment teeth: conventional crown

Question 15

What are single and double abutments used for?

Answer 15

Single abutment for cantilevered bridges and double abutment for fixed-fixed bridges.

Question 16

What are conventional cantilever bridges?

Answer 16

Bridges where the pontic is retained by a conventional crown, inlay, or onlay.

retention coming from 1 side only & conventional crown prep of that 1 abutment tooth

Question 17

What are indications for conventional bridgework?

Answer 17

• Heavily restored abutments.
• Well-motivated patients with good plaque control.
• No active caries.
• Stable periodontium.
• Maintainable bridgework.
• Small edentulous spaces.
• Replacement bridgework.

Question 18

What are contraindications for conventional bridgework?

Answer 18

Unrestored abutments.
Poorly motivated patients.
Active caries or periodontitis.
Poor manual dexterity.
Large edentulous spaces.
Contact sports players.

Question 19

Which teeth are ideal for bridge abutments?

Answer 19

1s, 3s, and 6s.

Question 20

why are 1s, 3s, and 6s. ideal bridge abutments?

Answer 20

• have long/multirooted roots
• sufficient in structure of clinical crown height to provide retention

Question 21

What teeth are unsuitable for abutments?

Answer 21

• Teeth with poor clinical and radiographic support.
• heavily restored with post crowns
• endo-treated with posts (already compromised so dont want to overload)

Question 22

What are resin-retained cantilever bridges?

Answer 22

Bridges where the pontic is retained by a metal retainer using cement and abutment coverage.

cantilver= one side only attachment
reesin retained= retained by a metal retainer using cement and abutment coverage.

Question 23

What are indications for resin-retained bridges?

Answer 23

Sound, unrestored abutments.
Well-motivated patients with excellent plaque control.
No active caries.
Stable periodontium.
Maintainable bridgework.
Small edentulous spaces.

Question 24

What are contraindications for resin-retained bridges?

Answer 24

Heavily restored abutments.
Poor crown height.
Poorly motivated patients.
Active caries or periodontitis.
Poor manual dexterity.
Large edentulous spaces.
Contact sports players.
Bruxism or parafunctional habits.

Question 25

What is a key design feature of resin-retained bridges?

Answer 25

Minimal tooth preparation of abutment to maximize enamel bonding.

Question 26

What did research conclude about resin-retained bridges?

Answer 26

They are superior in longevity and patient satisfaction compared to other designs.

Question 27

How should the abutment surface be prepared for resin-retained bridges?

Answer 27

Maximize coverage of the abutment tooth surface to maximise retention

Question 28

What is a key design feature for abutment teeth in bridges?

Answer 28

Cover the maximal surface area of the abutment tooth.

Question 29

in resin retained bridges, how do we overcome the fact that the metal wing bonded to the resin might interfere with the pts bite

Answer 29

overeruption of teeth

Question 30

What material and thickness should metal wing retainers have?

Answer 30

Rigid, non-precious metal with a thickness of 0.7(ant tooth`) -0.8mm (post tooth).

Question 31

What design is recommended for adhesive bridgework in terms of pontic?

Answer 31

Cantilever designs with the pontics kept out of excursive contacts.

Question 32

Which teeth are ideal as bridge abutments?

Answer 32

Canines and molars.

Question 33

Why should fixed-fixed resin-retained bridges be avoided?

Answer 33

They can lead to complications and are less reliable. when the bridges fail, they ususally fail at the wing-tooth interface, leading to degradation of cement, leaving a gap and then caries starts to develop if this is a fixed-fixed, then one of them fails but it will remain bonded thru the other abutment so u will only see that its failed once its quite a severe fail (caries and all)

Question 34

What is a cantilever bridge?

Answer 34

A prosthesis where the pontic is supported on one end by one or more abutments.

Question 35

what are the 2 types of cantilever briges?

Answer 35

Question 36

What is the clinical workflow for conventional bridges?

Answer 36

Primary impression. Diagnostic wax-up. Abutment preparation and master impression. Bridge construction. Bridge trial and cementation.

Question 37

What are design considerations for conventional bridges?

Answer 37

Keep pontic in light contact in ICP and no lateral/protrusive contacts. Share occlusal guidance with natural teeth.

Question 38

What is the clinical workflow for resin-retained bridges?

Answer 38

Primary impression. Diagnostic wax-up. Master impression. Bridge construction. Bridge trial and cementation.

Question 39

What are design considerations for resin-retained bridges?

Answer 39

Light contact for the pontic in ICP. Discuss anterior wax-up with patients. Inform patients that metal wings may show through.

Question 40

What are fixed-fixed bridges used for today?

Answer 40

As replacements for old bridges when abutments are sound.

Question 41

Why are fixed-fixed bridges not used in contemporary practice?

Answer 41

They are destructive and have long-term complications like caries and endodontic failure.

Question 42

What is the 10-year pulp survivability under a single MCC?

Answer 42

84.4%

Question 43

What is the 15-year pulp survivability under a bridge MCC abutment?

Answer 43

66.2%

Question 44

What is the leading cause of failure in single MCCs?

Answer 44

Endodontics (55.9%)

Question 45

What is the leading cause of failure in bridge MCCs?

Answer 45

Endodontics (53.3%)

Question 46

What is the survival rate of conventional cantilever bridges at 10 years?

Answer 46

81.8%

Question 47

What is the main complication of resin-retained cantilever bridges?

Answer 47

Debonding

Question 48

What is the survival rate of conventional fixed-fixed bridges at 10 years?

Answer 48

92%

Question 49

What is the risk of caries and endodontic failure for conventional fixed-fixed bridges?

Answer 49

Caries (38%), endodontic risk (32%)

Question 50

What are the main take-home messages for prosthodontic treatments?

Answer 50

Well-maintained teeth last a long time. Prosthodontic treatments have biological, technical, and financial consequences. Use diagnostic wax-ups and plan occlusal schemes. Choose the least destructive techniques. Consider the Shortened Dental Arch concept.