surveyed crowns Flashcards
when to make a surveyed crown
- tooth extensively destroyed
- reestablish occ plane
- to create proper rests, contours, etc
when is the cast surveyed and design drawn relative to crown making
before crown made
It is essential that recontouring procedures be completed _______ crown (fixed restoration) procedures
t is essential that re-contouring procedures be completed
before crown (fixed restoration) procedures are begun
survey crown rest made of:
metal
areas engaging retentive clasp are made of
metal or porcelin
guide planes of surveyed crown made of
metal
when prepping tooth for crown what should be considered?
consider GP and rests: more reduction in area of rests for adequete bulk of material
impression for prepped crown tooth
req a full arch impression
casts for survey crown prep
full arch cast with a removable die is used
on lab work authorization form what should be indicated?
retainer/
undercut?
rest?
material?
other?
Must indicate the RPD retainer selected (RPC, RPI,
etc) including height of contour details
Indicate the desired location and amount (0.1”, 0.2”,
0.3”) undercut for retentive arm
Indicate rest details (occlusal, cingulum, etc.)
Indicate material for rest (metal)
Indicate other metal ceramic requirements (shade,
occlusion, etc)
how are GP established for the surveyed crown
Guiding planes are created and refined using a wax knife in the vertical arm of a dental
surveyor.
surverying and adjustments for the crown
done on the wax pattern with the surveyor, can used carving instrument to establish proper contours
why would metal rests be more effective?
Dental ceramics are strong in compression, but weak in tension. If rest is permitted to
bind against the walls of a rest seat, wedging forces will result.
The accompanying tensile forces may result in failure of a
ceramic restoration
once crown is milled what should be done
crown should be surveyed