Denture Pros Exam Flashcards
what is kennedy class 1?
bilateral free end saddle
what is kennedy class 2?
unilateral free end saddle
what is kennedy class 3?
bound saddle not crossing midline
what is kennedy class 4?
bound saddle crossing midline
why is reciprocation required?
to prevent tooth movement
what should a clasp be when seated?
passive
what dimensions are required for a mid palatal bar?
7-12mm
what materials should be used for a gingivally approaching clasp?
cobalt chrome or stainless steel
give a benefit of an I bar
puts less stress on the tooth
name other types of clasp deisgn
ring clasp
occlusally approaching clasp
3 arm clasp
what crown height is required for a dental bar?
9mm
what is the bar width and gingival/incisal clearance for a dental bar?
5mm bar width
2mm clearance from gingival margin
2mm clearance from incisal tip
give a benefit of a dental bar design over a plate design?
more hygenic than plate design
when should a dental bar not be used?
when there’s spacing between teeth
what is a distinctive feature of the lingual bar? what do these do?
cummer arms - they provide indirect retention to prevent a posterior uplift
what sulcus depth is required for a lingual bar? how much clearance from the gingival margin should the lingual bar have?
7mm sulcus depth required
lingual bar should be 3.5mm away from gingival margin
when is the use of a lingual bar advantageous?
when the pt has anterior spacing
what undercut depth would Co/Cr clasps be used for?
0.25mm
what undercut depth would SS clasps be used for?
0.5mm
what undercut depth would gold clasps be used for?
0.75mm
what clasp material is the least and most flexible?
Co/Cr is least flexible
Gold is most flexible
how is undercut gauge used and what does it determine?
undercut gauge drawn up against the tooth
where the gauge touches the tooth is the point where the clasp should terminate (where terminal 1/3rd of clasp engages)
how does finishing point of SS clasp compare to finishing point of Co/Cr?
SS clasp finishes further down tooth further away from the survey line - as more flexible and engages a deeper undecrut
name 3 types of articulator
- plane line
- average value
- semi adjustable w/ facebow - has measurements written on it
what incisal angle and condyle width is average value set to?
incisal angle of 10 degrees
average condyle width = 25mm
what does a facebow record?
to record the relationship between the maxilla and TMJ
list 4 advantages of injection moulding over dough packing
- no flash in injection moulding which minimises the risk of an open bite when fitting the dentures
- no trial pack
- less handling of material required
- less pressure when injecting material
list 5 disadvantages of injection moulding over dough packing
- need to add sprue
- extra training required
- expensive
- difficult to de-flask - as you have the sprue to contend with as well
- technique sensitive
how does flash thickness affect denture thickness?
inc flash thickness increases denture thickness