Lecture 4-Class III and IV Design Flashcards
In a Class III situaiton denture bases, therefore, generally do not ______ or _____ away from the underlying tissues
ROTATE or LIFT
In a Class III situaiton compensation for ________ forces is not needed.
ROTATIONAL
The Class III can frequently be used as a valuable aid to ________ treatment because of its stabilizing influence on the remaining teeth
periodontal
In a Class III, denture base of Class III may be WHAT MATERIAL? since relining is not an ongoing concern…
metal
Is indirect retention necessary in a Class III?
NO!
Why is indirect retention NOT NECESSARY in a Class III?
there is no FULCRUM line!
In the Class IV arch the ______ line passes through the two abutments adjacent to the single edentulous space.
fulcrum
Forces acting to move the denture base away from the edentulous ridge in a Class IV RPD must be resisted by WHAT? positioned posterior to the fulcrum line.
indirect retainers
Forces acting to move the denture base IN WHICH DIRECTION? the edentulous ridge in a Class IV RPD must be resisted by indirect retainers positioned posterior to the fulcrum line.
AWAY FROM
Forces acting to move the denture base away from the edentulous ridge in a Class IV RPD must be resisted by indirect retainers positioned ________ to the fulcrum line.
POSTERIOR
WHAT TYPE of RESTS _________ provide effective indirect retention for CLASS IV framework.
Embrasure rests
Class IV is often a good indication for which retentive feature?
Rotational Path
Which feature is this describing?: Incorporates a curved or variable path of placement allowing one or more of the rigid components of the framework to gain access to and engage an undercut
Rotational Path
How do you usually classify a rotational path RPD?
Anterior to Posterior OR Posterior to Anterior
Generally, it is better treatment to replace missing teeth with a ______ restoration
FIXED
A notable exception for RPD over FPD is when ______ teeth are lost along with significant amounts of ________.
anterior…alveolar bone
What can you avoid when doing a Class IV RPD instead of an FPD?
long span pontics!
When feasible, close modification spaces with _____’s, ESPECIALLY free-standing _______ and _______ teeth.
FPD’s….premolars and anterior
Replacing free standing PM’s with FPD BECAUSE: free standing premolars cannot resist ______ forces
torquing
Replace anterior teeth with FPD’s because they tend to ROCK _______ and _______ when the distal extension is depressed.
superior and inferiorly
Extensive alveolar bone loss necessitating tooth replacement AND Alveolar Bone. is a good indication for a _______ RPD
Class IV
What are the two main goals when preparing an embrasure clasp?
- Dont open the contacts! 2.Lower the MR 1.5mm!
In Class I and II, what is the PRIMARY support for the RPD?
the underlying tissues!
In Class I and II, what is the SECONDARY support for the RPD?
the abutment teeth! (underlying tissues are primary!)
