Attachments in Removable Partial Dentures Flashcards
A mechanical device for the retention and stabilization of a prosthesis.
Attachment
What is the attachment component on an RPD?
Retainer
Why are attachments used?
1) Better esthetics.
2) Increase retention and stability.
Housed in the acrylic of the denture.
Patrix
Located in the root or an implant.
Matrix
Direct retainers are what type of attachment?
Extracoronal
Intracoronal direct retainers must be placed parallel to what?
1) Path of Insertion
2) Each other.
Kennedy classes where you use an intracoronal direct retainer.
3 and 4
Must be tooth-supported in order to have enough rigidity.
Types of intraocoronal direct retainers.
Precision or Semiprecision attachments
Type of intracoronal attachment that’s prefabricated and machined.
Precisely fitting components, tolerance to 0.01 mm.
Precision attachment
A type of intracoronal attachment that’s cast from plastic/wax patterns by the lab tech.
Semiprecision attachment.
What are semiprecision attachments often used for?
As stress-breakers, like in a pier abutment to allow for some rotation on a long-span bridge.
Positioned WITHIN the normal contours of the abutment.
Intracoronal attachments.
Positined OUTSIDE the normal contours of the abutment.
Extracoronal attachment.
Resilient definition
Allows for movement of the prosthesis.
This provides retention, but no stability or support.
Extracoronal attachments
Attachments used for Class I and II’s.
Extracoronal attachments
Rigid or non-rigid connector needed when you have TWO anterior implants connected by a bar?
Non-rigid
Allows the prosthesis to rotate anterior-posteriorly.
Rigid or non-rigid connector needed when you have FOUR implants connected by a bar?
Rigid!
This attachment allows for 0.4 mm of vertical resiliency.
ERA attachment
Extracoronal Radicular attachment
Weird looking attachment.
Dalbo attachment
These attachments can direct forces closer to the center of the tooth.
Intracoronal attachments.
Disadvantages of attachments.
1) The abutments rewuire crowns.
2) Additional reduction is needed to fir the components (intracoronal).
3) Require a LOT of INTEROCCLUSAL space (4-6 mm).
4) More expensive.
How much interocclusal space is needed for attachments?
4-6 mm
T/F:
Whenever a conventional clasp assembly can be used, it should be considered as the direct retainer of choice.
True
Contraindications for Attachments:
- Poor periodontal health.
- Poor crown to root ratio.
- Compromized endo or restorative conition.
- Poor oral hygiene.
- Inadequate manual dexterity of the patient.
