Indirect retainers

Question 1

The component of a RPD that assists the direct retainer in preventing displacement of the distal extension denture base by functioning through lever action on the opposite side of the fulcrum line when the denture base moves away from the tissues in pure rotation around the fulcrum line.

Answer 1

indirect retainer

Question 2

❑Prevents movement of the distal extension base away from the residual ridge
❑Converts Class I lever to Class II lever

Answer 2

Indirect retainer

Question 3

Function of \_\_\_\_\_\_\_:
imit RPD vertical dislodgement
❑Reduce leverage on abutments
❑Reduce tissue impingement by mandibular major connectors
❑Increase RPD stability & support
❑Stabilize the framework during relining

Answer 3

Indirect Retainer

Question 4

❑Usually a rest located on the opposite side of the fulcrum line that assist the direct retainer in resisting movement of the RPD in an occlusal direction-like when eating sticky food

Answer 4

Indirect retainer

Question 5

❑Usually in the form of an auxiliary rest
❑Ideal position is perpendicular to fulcrum line
❑Place as far forward of fulcrum line as possible

Answer 5

Indirect retainer

Question 6

The ______ the distance between the fulcrum line and the indirect retainer, the more effective the direct retainer will be.

Answer 6

greater

Question 7

Is lingual plating enough for an indirect retainer?

Answer 7

No

Question 8

If a lingual plate major connector is used, what must be added to achieve the functionality of an indirect retainer?

Answer 8

Rests at each end

Question 9

What 2 Kennedy classes are indirect retainers required?

Answer 9

1 and 2

Question 10

How many indirect retainers are needed in a class 1?

Answer 10

2 indirect retainers

Question 11

How many indirect retainers are needed in a class 2?

Answer 11

1 indirect retainer

Question 12

The indirect retainer is placed on the ____ side of the fulcrum line from direct retainers so the denture base doesn’t move away from tissues in pure rotation

Answer 12

Opposite

Question 13

❑_______ occurs around most distal rests

❑Resisted by rests and denture base

Answer 13

Rotation

Question 14

______-supported RPD denture base:

1. Support prosthetic teeth
2. Esthetics: replace missing tissue
3. Horizontal stability

Answer 14

Tooth supported

Question 15

______-supported RPD denture base:

1. Support prosthetic teeth
2. Esthetics: replace missing tissue
3. Horizontal stability
4. Vertical support
5. Secondary retention: interfacial surface tension between base & underlying mucosa

Answer 15

Tooth-tissue supported

Question 16

More surface area of coverage by denture base leads to _____ stress

Answer 16

Less stress

Question 17

If the tissue of the the residual ridge is more displaceable, there is ____ support

Answer 17

Less support

Question 18

_____ bone has better support than cancellous

Answer 18

Cortical

Question 19

What are the 4 factors affecting denture base support of distal extension RPD?

Answer 19

Quality of Soft Tissue over ridge
Type of BOne
Amount of denture base coverage
Accuracy of fit of the denture base

Question 20

Requirements of an Ideal ________

1. Accurate & dimensionally stable
2. Tissue compatibility
3. Thermal conductivity
4. Low specific gravity: light weight
5. Sufficient strength: resist fracture
6. Esthetic
7. Potential for future reline

Answer 20

Denture Base Material

Question 21

\_\_\_\_\_\_\_ denture base material:
l❑Difficult to adjust
❑Poor esthetics
❑Part of cast framework
❑Good thermal conductivity
❑Can be kept thin:
❑Advantage where inadequate inter-arch space

Answer 21

❑Metal

Question 22

\_\_\_\_\_\_\_ denture base material:
❑Most common
❑Easily adjusted & relined
❑Good esthetics
❑Attachment to framework by lattice or mesh

Answer 22

❑Polymethylmethacrylate (PMMA)/Acrylic resin

Question 23

Denture base retention on mandibular arch extends how to what point

Answer 23

2/3 distance to retromolar pad

Question 24

Denture base retention on maxillary arch extends how to what point

Answer 24

2/3 distance to hamular notch

Question 25

______ denture base retention:
❑Two struts of metal
❑Extend longitudinally along residual ridge
❑Positioned buccal & lingual to ridge crest
❑Avoid longitudinal strut along ridge crest
❑Interferes with tooth placement
❑Cleavage action occurs within denture base
❑Strongest attachment
❑Easiest to reline
❑Preferred retention

Answer 25

Lattice retention

Question 26

______ denture base retention:
❑Thin sheet of metal with multiple holes
❑Extension over ridge similar to lattice
❑Inferior attachment strength

Answer 26

Mesh retention

Question 27

A ______ is essential to prevent displacement or deformation of the metal framework during resin-packing procedures.
❑Projects from the tissue surface of the minor connector to contact the dental cast.

Answer 27

cast stop

Question 28

All internal finish line angle between acrylic resin and metal components should be ______ degrees

Answer 28

90 degrees

Question 29

All internal angles of external finish line should be ______ degrees

Answer 29

Less than 90 degrees

Question 30

\_\_\_\_\_ teeth:
❑Most common
❑Easily adjusted
❑Not wear opposing natural dentition
❑Chemical bond with denture base

Answer 30

❑Acrylic

Question 31

\_\_\_\_\_\_ teeth:
❑Fracture easily
❑Wear opposing dentition
❑Difficult to adjust
❑Mechanical retention only to denture base

Answer 31

❑Porcelain

Question 32

_____ teeth:
❑Denture tooth with drilled channel
❑Secured to metal post
❑Used with metal base: inadequate interarch space

Answer 32

❑Tube teeth

Question 33

_________
❑Composite resin polymerized around projections of metal from denture base
❑Anterior teeth only
❑Inadequate interarch space

Answer 33

❑Reinforced acrylic pontics(RAPs)

Question 34

\_\_\_\_\_\_ teeth
❑Used with severely inadequate interarch space
❑Poor esthetics
❑Used only in posterior
❑Difficult to adjust

Answer 34

Metal teeth