rpd osce Flashcards
what are saddles?
the teeth being replaced by RPD
what is seen in a patient with Kennedy Class I ?
bilateral free end saddle
what is seen in a patient with Kennedy Class II?
Unilateral free end saddle
what is seen in a patient with Kennedy Class III ?
bounded saddle
what is seen in a patient with Kennedy Class IV ?
anterior bounded saddle that crosses the midline
if there are multiple saddles, what saddle is the Kennedy Classification score based on?
the MOST POSTERIOR saddle
what is support defined as in relation to RPD design?
the resistance of the denture to occlusally directed load
what is seen in a patient with Craddock Class 1?
tooth borne support
what is seen in a patient with Craddock Class 2?
mucosa borne support
what is seen in a patient with Craddock Class 3?
combination of tooth and mucosa borne support
what is retention defined as in relation to RPD design?
the resistance of the denture to vertical displacement/lifting away from the tissues
What are the different methods of providing retention to an RPD?
clasps
soft tissue undercuts
path of insertion
adhesion
what is indirect retention defined as in relation to RPD design?
the resistance of the denture to rotational displacement
what is indirect retention provided by?
rests! (not clasps)
what is reciprocation defined as in relation to RPD design?
reciprocation prevents a clasped arm moving a clasped tooth
what are the undercut gauges used when surveying for clasps?
- 25mm
- 50mm
- 75mm
There is an undercut of 0.25mm, what material would the clasp be made of?
Cobalt Chromium
There is an undercut of 0.5mm, what material would the clasp be made of?
wrought gold
There is an undercut of 0.75mm, what material would the clasp be made of?
stainless steel
What method of support is better, tooth borne or mucosa borne? WHY?
TOOTH BORNE
- transmits load via periodontal ligament, more natural for patient
- more comfortable for patient
- protects soft tissue from trauma
Why are the problems with Mucosal Support?
Must cover as large an area as possible or there will be REDUCTION OF OCCLUSAL TABLE
Allows the denture base to move slightly which can cause TRAUMA TO ADJACENT GINGIVAL MARGINS
What load of support can a healthy tooth carry? (potentially)
A healthy tooth can potentially carry its own load plus one and a half similar teeth
What teeth are best for providing support?
1st = molars 2nd = canines 3rd = premolars
What teeth should be avoided when looking to provide support?
the incisors
lower incisors are weakest teeth in the arch (smallest root)
How should rests be positioned?
Rests positioned so that they transfer load through the long axis of the tooth to prevent tilting
Why shouldn’t the denture base be positioned within 3mm of the gingival margin?
Soft tissue is compressible, this will place pressure at the gingival margin