Direct Retainers (Part I)

Question 1

RPD retention resists::

Answer 1

Dislodging forces

Question 2

Mechanical retention from retaining elements on abutment teeth:

Answer 2

Primary retention

Question 3

Retention due to the intimate contact of minor connector with guid planes:

Answer 3

Secondary retention

Question 4

Retention due to the intimate contact of denture base & maxillary major connector with underlying tissues:

Answer 4

Secondary retention

Question 5

RPD component used to retain and prevent dislodgment:

Answer 5

Direct retainer

Question 6

What are the two types of direct retainers?

Answer 6

1. Intracoronal
2. Extracoronal

Question 7

Type of direct retainer characterized by internal precision attachment (key/keyway):

Answer 7

Intracoronal

Question 8

What type of direct retainer is considered the most esthetic?

Answer 8

Intracoronal

Question 9

What are the disadvantages to an intracoronal direct retainer?

Answer 9

Requires crown, complex fabrication & high maintenance

Question 10

What type of direct retainer is more commonly used?

Answer 10

Extracoronal

Question 11

Type of direct retainer characterized by a clasp assembly:

Answer 11

Extracoronal

Question 12

What are two types of clasps?

Answer 12

1. Suprabulge
2. Infrabulge

Question 13

Type of clasp in which the retentive arm approaches undercut from above the survey line:

Answer 13

Suprabulge

Question 14

Suprabulge clasps may also be referred to as:

Answer 14

Circumferential, Akers, circlet

Question 15

Type od clasp in which the retentive arm approaches undercut from below survey line:

Answer 15

Infrabulge

Question 16

An infrabulge clasp may also be referred to as:

Answer 16

Bar clasps

Question 17

What type of direct retainer is seen in the following image?

Answer 17

Intracoronal

Question 18

What type of direct retainer is seen in the following image?

Answer 18

Extracoronal

Question 19

What type of clasp is seen in the following image?

Answer 19

Suprabulge

Question 20

What type of clasp is seen in the following images?

Answer 20

Infrabulge

Question 21

Label the following components of the supra-gingival clasp assembly:

(Top to bottom)

Answer 21

Rest
Reciprocal clasp
Retentive clasp
Proximal plate

Question 22

Label the types of clasps seen in the following image:

Answer 22

A) Suprabulge clasp
B) Infrabulge clasp

Question 23

A properly constructed suprabulge or infrabulge clasp assembly must incorporate the following components: (4)

Answer 23

1. a rest
2. a retentive clasp
3. a reciprocal element
4. one or more minor connectors

Question 24

Label the following parts of the clasp assembly:

Answer 24

A) Retentive clasp arm
B) Rest
C) Minor connector
D) Reciprocal arm

Question 25

Label the following components:

Answer 25

A) Direct retainer B) Rest C) Reciprocal arm D) Direct retainer E) Reciprocal plate

Question 26

Component of the clasp assembly that lies on occlusal, lingual or incisal surface and functions to precent tissueward movement of clasp:

Answer 26

Rest

Question 27

What is the function the rest component of a clasp assembly?

Answer 27

Prevent tissueward movement of clasp

Question 28

Label each type of rest seen in the following image: (Left to right)

Answer 28

Occlusal rest, Cingulum chevron rest, lingual ball rest, incisal rest

Question 29

Where might the rest component of a clasp assembly lies on?

Answer 29

1. Occlusal surface 2. Lingual surface 3. Incisal surface

Question 30

Rigid component of a clasp assembly that is above the heigh of contour:

Answer 30

Reciprocal components

Question 31

Reciprocal components of the clasp assembly include:

Answer 31

1. Reciprocal clasp 2. Lingual plate 3. Proximal plate 4. Guide plate (minor connectors)

Question 32

What clasp assembly component is seen in the following image?

Answer 32

Reciprocal components

Question 33

Clasp assembly component characterized by the rigid portion, above the height of contour; proximal 2/3:

Answer 33

Retentive clasp arm

Question 34

Clasp assembly component characterized by the flexible portion, below the height of contour; distal 1/3; provides direct retention:

Answer 34

Retentive terminal

Question 35

What is the function of the retentive terminal?

Answer 35

Provides direct retention

Question 36

Clasp assembly component that is described as rigid, and functions to join the body of clasp to the framework:

Answer 36

Minor connector

Question 37

The arrow in the following image is pointing to the:

Answer 37

Minor connector

Question 38

Clasp assembly component that is a component of a bar clasp that connects the clasp to the framework and is described as the flexible minor connector:

Answer 38

Approach arm

Question 39

What clasp assembly component is seen in the following image?

Answer 39

Approach arm

Question 40

List the six clasp assembly components:

Answer 40

1. Rests 2. Reciprocal components 3. Retentive clasp arm 4. Retentive terminal 5. Minor connector 6. Approach arm

Question 41

What are the six requirements of a clasp assembly?

Answer 41

1. Support 2. Stability 3. Encirclement of more than 180 degrees 4. Reciprocation 5. Passivity 6. Retention

Question 42

What do we mean when we say "support" is a requirement of a clasp assembly? What component provides this?

Answer 42

Resists vertical movement toward tissue; rests

Question 43

What do we mean when we say "stability" is a requirement of a clasp assembly? What component provides this?

Answer 43

Resists horizontal displacement; all areas above the survey line & all rigid components of direct retainer

Question 44

What do we mean when we say "Encirclement of more than 180 degrees" is a requirement of a clasp assembly? Describe?

Answer 44

Prevents tooth from moving away from the clasp; may be continuous or broken; minimum of 3 points used

Question 45

What requirement of clasp assembly is represented in the following image?

Answer 45

Encirclement of more than 180 degrees

Question 46

What requirement of clasp assembly is NOT met in the following image?

Answer 46

Encirclement of more than 180 degrees

Question 47

When discussing the "reciprocation" requirement of clasp assembly, the reciprocal component must contact tooth at:

Answer 47

Same time or sooner than retentive clasp

Question 48

When discussing the "reciprocation" requirement of clasp assembly, the reciprocal component must remain in contact while:

Answer 48

Retentive tip passes over height of contour

Question 49

When discussing the "reciprocation" requirement of clasp assembly, the reciprocal component must resist:

Answer 49

Retentive tip lateral forces

Question 50

When discussing the "reciprocation" requirement of clasp assembly, this requires ______ to pathogenicity of insertion

Answer 50

Parallel surface

Question 51

In the following image, the red arrow is pointing at:

Answer 51

Reciprocal clasp

Question 52

What do we mean when we say "Passivity" is a requirement of a clasp assembly?

Answer 52

Components of direct retainer exert no force when fully seated

Question 53

What do we mean when we say "Retention" is a requirement of a clasp assembly?

Answer 53

Resists displacement of RPD away from supporting tissues

Question 54

What area of the clasp assembly serves to satisfy the "retention" requirement of the clasp assembly?

Answer 54

Area below the survey line; ideally in the gingival 1/3

Question 55

Where does the clasp arm tip need to be in order to satisfy the "retention" requirement of clasp assembly?

Answer 55

Terminal 1/3 below survery line