pros Flashcards
what type of special tray is used for ZnOE major imp
close-fitting 0.6mm spacer
when might you use alginate or silicone for complete major imps
if extensive undercuts are present - request spaced tray
how short of sulcus should special tray finish
2mm
advantages of using permanent acrylic base for reg
check for comfort + retention early
optimise accuracy of jaw relations
disadvantage - risk permanent base deforming in second cure
how should pts occlude when assessing reg for completes
retruded arc of closure - tongue to roof of mouth
2 things to check when checking blue mouse reg for c/c
- check no heal clash
2. check can be relocated
articular mounting technique used for c/c
split cast technique
3 types of porosity in acrylic
contraction
gaseous
granular
what is contraction porosity
insufficient acrylic dough or insufficient pressure during curing
porosity across whole denture base
what is gaseous porosity
temperature raised too high - porosity mostly in honest part = lingual flanges
what is granular porosity
evaporation of monomer during preparation
blotchy opaque surface
3 factors that show occlusion is good c/c
- occlusal pressure on both sides of mouth the same
- occlusal contacts indicated by articulating paper on premolar/molar region
- lateral + protrusive movement possible without cusp interference causing displacement
what is a check record
used when a lot of occlusal adjustment needed at finish
wax placed on lower post teeth + adjusted in retruded jaw relation for even contacts
denture placed on articulator + wax used to aid refinement
advantage of rebase
doesn’t increase thickness of palate
why might denture cause localised pain in lower premolar region
pressure on superficial mental nerve
when are alterations to compete denture made?
at first stage - before impression
how would you alter occlusion when making a copy denture
wax wafer used - before impression
3 stages of copy denture
- alterations + alginate impression
- try-in + major imp
- finish
how to take major imp for copy denture
remove undercuts, reduce peripheral border
modify using greenstick
ZnOE
closed mouth technique - even occlusal relationships should be maintained
advantages of immediate denture
aesthetics muscles adapt easier function maintained easier to reg if teeth remaining haemorrhage control
disadvantages of immediate denture
good cooperation
alveolar bone resorption
increased cost
try-in normally not possible
advantages of overdentures
maintenance of bone proprioceptive feedback retention assistance in control of masticatory force position of mandible during function reduction of psychological trauma
which teeth make the best abutments
canines + molars
size of undercut cocr clasp engages
0.25mm
