Design 2 Flashcards
in relation to the gingival margins where should connectors be located
either completely away from or completely covering
for rpds with little tooth support what type of connector would be best and why
plate would be best as offers more mucosal support to make up for lack of tooth support
is a bar or a plate a better option for craddock class 2 rpds
plate as more mucosal support
what is the default major connector for the mandibular arch and why
lingual bar as lingual surface has little space for plate
what is thicker cross sectionally a plate or a bar
bar
is a bar or a plate better for craddock class one rpds
bar - tooth support present therefore mucosal support not as important
disadvantage of plate connector
more mucosal coverage
may cover gingival margins and possibly irritate
disadvantage of bar connector
quite thick meaning not all patients will tolerate well
closed saddle design
no space between saddle and abutment for saliva to pass through
provides better retention however more mucosal coverage therefore greater chance of irritation
open saddle design
space between saddle and abutment for saliva to pass through
less mucosal coverage therefore less chance of irritation however less retentative features
what is an RPI
stress relieving clasp system
prevents stress on abutment teeth of free end saddles
what arch are RPI’s more commonly used in and why
mandibular
less of a need in the maxillary as the hard palate provides support
why are RPIs needed
difference in compressibility between periodontium of abutment and mucosa beneath free end saddle sees uneven compressibility
this can cause torquing of the abutment tooth as it tries to prevent tipping which risks damaging its PDL’s and therefore risks loss of the abutment tooth
what does RPI stand for
(mesial) Rest
Proximal guide plate
I bar clasp - gingivally approaching
