s8-Finals-Bridge design

Question 1

What are the main consequences of tooth removal without replacement?

Answer 1

Altered gum level, decay, extrusion, tipping, spacing, periodontal disease, bone loss

Question 2

Why is replacing missing teeth important for oral functionality?

Answer 2

To maintain masticatory ability/efficiency and preserve health of soft/hard tissues

Question 3

What are the advantages of implant-supported prostheses over conventional bridges?

Answer 3

Better preservation of adjacent teeth, improved long-term prognosis, suitable for free-end cases

Question 4

When is a tooth-supported fixed dental prosthesis contraindicated?

Answer 4

When abutment teeth have poor crown-root ratio, inadequate bone support, or poor prognosis

Question 5

What are the components of a conventional tooth-supported FPD?

Answer 5

Abutment teeth, pontic, connectors (rigid/non-rigid), retainers

Question 6

What makes fixed-fixed bridge designs biomechanically favorable?

Answer 6

Even stress distribution between abutments and better stability/retention

Question 7

When are double abutments recommended in bridge design?

Answer 7

For long spans, unfavorable crown-root ratios, tilting/drifting, or bone loss

Question 8

What are the requirements for using a third molar as an abutment?

Answer 8

Must be upright, fully erupted, with long separate roots and healthy gingival cuff

Question 9

What are the indications for fixed-supported (non-rigid connector) bridges?

Answer 9

Mobile teeth needing splinting, pier abutments, or when parallel preparations are difficult

Question 10

How does a non-rigid connector function in a fixed-supported bridge?

Answer 10

Allows movement between segments while maintaining prosthesis integrity

Question 11

What are the biomechanical risks of cantilever bridges?

Answer 11

Lever forces causing abutment tipping, rotation, or drifting

Question 12

What are the ideal abutment requirements for cantilever FPDs?

Answer 12

Long roots, favorable configuration, good crown-root ratio, healthy periodontium

Question 13

When is a cantilever design appropriate for replacing a maxillary lateral incisor?

Answer 13

When using canine as single abutment with minimal occlusal contact on pontic

Question 14

Why are cantilever bridges declining in use for molar replacement?

Answer 14

Due to better alternatives like dental implants

Question 15

What was the spring cantilever bridge design used for historically?

Answer 15

Replacing upper central or lateral incisors

Question 16

How does a telescopic (fixed-detachable) bridge work?

Answer 16

Uses inner coping cemented to abutment and outer removable crown/bridge

Question 17

What are the advantages of telescopic bridges?

Answer 17

Minimizes destructive torque, enhances vertical forces, allows retrievability

Question 18

What are the key features of resin-bonded bridges?

Answer 18

Minimal tooth preparation, metal/ceramic wings bonded to abutment palatal surfaces

Question 19

When are resin-bonded bridges most appropriate?

Answer 19

For single tooth replacement in young patients with intact abutments

Question 20

What are the limitations of inlay-retained bridges?

Answer 20

Less retention than full-coverage designs, higher risk of debonding

Question 21

What are hybrid bridge designs?

Answer 21

Combinations of partial and full coverage retainers in the same prosthesis

Question 22

Why is maxillary canine replacement particularly challenging?

Answer 22

Pontic lies outside interabutment axis, creating high lateral forces

Question 23

What abutments are typically used for maxillary canine FPDs?

Answer 23

Lateral incisor (weakest), central incisor (added), and first premolar

Question 24

Why is mandibular canine replacement less stressful than maxillary?

Answer 24

Lies within interabutment axis, creating no leverage

Question 25

When is an implant preferred over a conventional FPD for single tooth replacement?

Answer 25

When adjacent teeth are intact or when preserving tooth structure is priority

Question 26

What are the two main options for replacing a missing maxillary central incisor?

Answer 26

Implant or 3-unit full coverage fixed-fixed bridge

Question 27

How can a diastema be managed when replacing a central incisor?

Answer 27

Implant with maintained space, cantilever, or fixed-fixed bridge with loop connector

Question 28

What are disadvantages of loop connectors in bridges?

Answer 28

Difficult hygiene, speech interference, additional lab procedures

Question 29

What are the options for severely reduced mesio-distal width cases?

Answer 29

Maintain space with prosthetic replacement or close space orthodontically/restoratively

Question 30

How can digital smile design (DSD) help in bridge planning?

Answer 30

Allows digital measurements, wax-ups, and patient approval before treatment

Question 31

What are three solutions for abnormal occluso-gingival ridge defects?

Answer 31

Shape pontic to simulate root, use pink porcelain, perform ridge augmentation

Question 32

What is the purpose of ridge augmentation in bridge design?

Answer 32

To restore alveolar bone contour for proper pontic emergence and aesthetics

Question 33

How does Andrew's bridge design address gross bone defects?

Answer 33

Through non-surgical prosthetic compensation without ridge augmentation

Question 34

What factors influence the choice between fixed and removable prostheses?

Answer 34

Abutment condition, span length, patient expectations, cost, oral hygiene

Question 35

Why is occlusal analysis critical in bridge design?

Answer 35

To ensure proper force distribution and prevent biomechanical failure

Question 36

What is the minimum number of abutments typically required for a cantilever bridge replacing one tooth?

Answer 36

Two abutments, except when replacing a maxillary lateral incisor (canine alone may suffice)

Question 37

Why should rotated or malaligned teeth be avoided as cantilever abutments?

Answer 37

They cannot properly resist lateral forces and may lead to bridge failure

Question 38

What occlusal scheme is ideal when using a cantilever design for a premolar pontic?

Answer 38

Canine-protected occlusion to reduce lateral forces

Question 39

What is the key biomechanical difference between fixed-fixed and fixed-supported bridges?

Answer 39

Fixed-fixed distributes stress equally; fixed-supported allows movement at one connector

Question 40

Why are non-rigid connectors used with pier abutments?

Answer 40

To prevent the pier from acting as a fulcrum and stressing retainers

Question 41

What laboratory feature characterizes a precision attachment in fixed-supported bridges?

Answer 41

T-shaped key on the pontic and dovetail keyway in the retainer

Question 42

How does a resin-bonded bridge achieve retention?

Answer 42

Through adhesive bonding of wings to minimally prepared enamel

Question 43

What abutment condition contraindicates a resin-bonded bridge?

Answer 43

Large restorations, insufficient enamel, or heavy occlusion

Question 44

Why are zirconia resin-bonded bridges advantageous over metal counterparts?

Answer 44

Better aesthetics and biocompatibility

Question 45

What is the primary drawback of inlay-retained bridges compared to full-coverage designs?

Answer 45

Lower retention due to limited preparation depth

Question 46

When might a hybrid design combine partial and full coverage retainers?

Answer 46

When abutments have varying needs (e.g., weak premolar vs. strong canine)

Question 47

Why must maxillary canine pontics be designed with care?

Answer 47

Their position outside the interabutment axis creates destructive leverage

Question 48

What occlusal adjustment reduces stress on a maxillary canine FPD?

Answer 48

Group function or canine guidance to distribute lateral forces

Question 49

Why is mandibular canine replacement biomechanically simpler?

Answer 49

The pontic lies within the interabutment axis, minimizing leverage

Question 50

When is a 3-unit FPD contraindicated for a single missing tooth?

Answer 50

If adjacent teeth are unrestored and healthy (implant preferred)

Question 51

What diagnostic tool helps plan pontic shape for ridge defects?

Answer 51

Diagnostic wax-up to simulate crown/root emergence

Question 52

How does pink porcelain improve bridge aesthetics in ridge defects?

Answer 52

Mimics gingival tissue to mask alveolar bone loss

Question 53

What are the three classes of residual ridge defects?

Answer 53

Class I (minimal loss), II (moderate), III (severe/knife-edge)

Question 54

When is ridge augmentation preferred over prosthetic compensation?

Answer 54

For large defects where pontic adaptation would compromise hygiene/aesthetics

Question 55

What is the key advantage of digital workflows in bridge design?

Answer 55

Precise planning (CBCT, DSD) and reduced manual errors

Question 56

How does a 3D-printed model aid bridge fabrication?

Answer 56

Allows mock-ups and provisional testing before final restoration

Question 57

What is Ante’s Law, and how does it guide abutment selection?

Answer 57

Root surface area of abutments must equal/exceed that of missing teeth

Question 58

Why are secondary abutments added in long-span FPDs?

Answer 58

To compensate for unfavorable crown-root ratios or excessive span length

Question 59

What is the maximum number of missing teeth typically replaceable with a fixed prosthesis?

Answer 59

3–4 teeth, depending on abutment strength and arch position

Question 60

How does pontic design differ for molar vs. anterior replacements?

Answer 60

Molars: functional contour; anteriors: aesthetic emergence profile

Question 61

What are the contraindications for cantilever molar bridges?

Answer 61

Poor abutment support, parafunctional habits, or excessive occlusal load

Question 62

Why are telescopic bridges used in compromised dentitions?

Answer 62

To distribute forces and allow prosthesis maintenance/replacement

Question 63

What is the role of parallelism in telescopic crowns?

Answer 63

Ensures friction fit and prevents destructive horizontal forces

Question 64

How does a non-rigid connector reduce stress on abutments?

Answer 64

Allows slight movement to dissipate occlusal forces

Question 65

What are the four key factors in selecting bridge design?

Answer 65

Abutment condition, span length, occlusion, and patient factors (cost/hygiene)

Question 66

Why are implants preferred over FPDs for free-end edentulous spaces?

Answer 66

Avoids cantilever forces and preserves adjacent teeth

Question 67

What is the "ferrule effect," and why is it critical for abutments?

Answer 67

2 mm of vertical tooth structure for crown retention and fracture resistance

Question 68

How does occlusal force magnitude influence bridge design?

Answer 68

Higher forces require more abutments or rigid designs

Question 69

What are the consequences of ignoring crown-root ratios in abutment selection?

Answer 69

Increased risk of abutment failure due to excessive mobility

Question 70

What is the purpose of a "wash-through" pontic design?

Answer 70

Facilitates hygiene in mandibular molar replacements