Direct Retainers Part I Flashcards
RPD retention resists:
dislodging forces
Mechanical retention from retaining elements on abutment teeth:
primary retention
Retention due to the intimate contact of minor connector with guide planes
secondary retention
Retention due to intimate contact of denture base & maxillary major connector with underlying tissue:
secondary retention
RPD component used to retain and prevent dislodgment:
direct retainer
direct retainer with internal precision attachment: key/ keyway
intracoronal
What type of direct retainer is most esthetic?
intracoronal
What are the disadvantages to an intracoronal direct retainer?
require crown, complex fabrication, & high maintenance
Direct retainer with clasp assembly:
extracoronal
What type of direct retainer is most commonly used?
extracoronal
Clasp types include:
- suprabulge
- infrabulge
What are the two types of direct retainers?
- intracoronal
- extracoronal
This image shows a:
intracoronal direct retainer
This image show a:
extra coronal direct retainer
What type of clasp is shown?
suprabulge
What type of clasp is show?
infrabulge
Clasp type:
- retentive arm approaches undercut from above the survey line
suprabulge
Clasp type:
- retentive arm approaches undercut from below survey line
- contains bar clasps
infrabulge
Circumferential, Akers, and Circlet are all synonyms for what clasp type?
suprabulge
What clasp type contains bar clasps?
infrabulge
From top to bottom the parts of the supra-gingival clasp assembly include:
- rest
- reciprocal clasp
- retentive clasp
- proximal plate
Label the types of clasps seen in the following image:
top: suprabulge
bottom: infrabulge
A properly constructed suprabulge or infrabulge clasp assembly must incorporate the following components:
- Rest
- Retentive clasp
- Reciprocal element
- One or more minor components
Label the following parts of the clasp assembly:
A: retentive clasp arm
B: rest
C: minor connector
D: reciprocal arm
Label the parts of the image:
A: Direct Retainer
B: Direct Retainer
C: Reciprocal Plate
D: Reciprocal Arm
E: Rest
Clasp assembly component that lies on occlusal, lingual, and incisal surface, that prevents tissue ward movement of clasp:
Rest
Label the types of rests shown: (from left to right)
- occlusal rest
- cingulum chevron rest
- lingual ball rest
- incisal rest
What is the function of the rest? (component of clasp assembly)
prevents tissue ward movement of clasp
- rigid component
- above heigh of counter
- reciprocal clasp
- lingual plate
- proximal plate
- guide plate (minor connectors)
Reciprocal components
The retentive clasp arm is located in the:
proximal 2/3
Retentive clasp arm is the ___ portion
rigid portion
The retentive terminal is located in the:
distal 1/3
The retentive terminal can be described as:
flexible
The retentive terminal is ____ the height of contour
below
The retentive clasp arms are located ___ the height of contour
above
What provides direct retention? (retentive terminal or retentive clasp arm)
retentive terminal
What type of retention is provided by the retentive terminal?
direct
clasp assembly component that joins the body of clasp to framework:
minor connector
The minor connector can be described as:
rigid
This image is showing the:
minor connector
Component of the bar clasp that connects the clasp to framework:
approach arm
The 6 requirements of clasp assembly include:
- support
- stability
- encirclement of MORE THAN 180 degrees
- reciprocation
- passivity
- retention
What component of clasp assembly is involved with support?
rests
Requirement of clasp assembly that resists vertical movement toward tissue:
support
Support resists ____ movement toward ____.
vertical movement toward tissue
Requirement of clasp assembly that resists horizontal displacement:
stability
What components of clasp assembly are involved with “stability”?
all rigid components of direct retainer
Requirements of clasp assembly (STABILITY)
