design principles Flashcards
what are the alternative treatments to rpds?
none fixed prosthesis -conventional -renin-bonded implants
what are the 7 aspects of design?
saddles support retention indirect retention bracing/reciprocation connectors review & simplify
which kennedy classification should you opt for if unsure?
the lowest
modifications if more saddles
what is kennedy class 1?
bilateral free end saddle
what is kennedy class 2?
unilateral free end saddle
what is kennedy class 3?
bounded saddle
what is kennedy class 4?
anterior bounded saddle crossing midline
what is a modification?
extra bounded saddle
what is support?
the resistance of the denture to occlusally directed load
why is tooth borne preffered?
best support, most stable, teeth don’t move as much, mucosa has elasticity, so denture will bounce
what is retention?
resistance of the denture to vertical displacement (lifting away from the tissues)
what are the methods of retention?
clasps soft tissue undercuts adhesion (maxillary plates) friction path of insertion precision attachments/implants
what is indirect retention?
resistance to rotational displacement
what is reciprocation?
prevents a clasp arm moving the clasped tooth
-arm on opposing side
what is a major connector?
connects all the components
what is a minor connector?
connects rests, clasps, and bracing arms
what are the connector options?
bar
horseshoe
plate PMMA/CoCr
what are the 2 types of bar?
mid palatal strap, thin, broad, doesn’t interfere with tongue
ring - stays away from ginigival margins of non-abutment teeth
easy to clean
thin, broader rings better tolerated
describe a horseshoe design
anterior and lateral saddles, keep palate clear, well accepted
what can plates be made of?
acrylic - cheaper, thicker
cobalt chrome - heavier, less elastic
what factors decide the craddock class?
periodontal condition of abutments size and position of saddle/abutments condition of supporting mucosa occlusion/chewing ability aesthetics
why is a rest seat place on each crown?
more confortable
what way can clasps increase retention?
support on all sides of bounded saddles
where on the tooth should rests be placed?
in the direction of the replaced tooth
how are rests described?
position on tooth eg mesial
what tooth is ideal for indirect retention and why?
canine- due to large root can withstand pressure
-can utilise cingulum
