Before Midterm: Survey Crown Flashcards
Structures that must be captured in impression for RDP:
teeth, residual ridges,
Factors to be considered when making an impression
materiall, technique
Most common reason for lack of accuracy of impression:
distortion of material
Tray for 1’ impression:
stock
How to get functional form for RPD:
pour up as master cast, send to lab, framework comes back, another impression of distal extended area,
Step for impression making for RPD:
stock tray: diagnostic impression, dx cast, custom tray: secondary impression, master cast prep, corrected impression when indicated in distal extension RPF
Pt positioning for alginate impressions:
upright, occlusal plane parallel to the floor
Where to stand for mandibular impressions;
to R and infront of pt
Where to stand for maxillary impressions:
to R and behind pt
4 types of stock impression trays for dentate and partially edentulous arches:
non-perforated or plastic, perforated metal or plastic
Clearance needed for maxillary or mandibular trays:
4-5mm facial and lingual
How thick should the alginate be?
4-5mm
What to tell pt when taking max impression:
relax your jaw
How to modify impression trays:
wax or modeling plastic
The tray should cover these landmarks in the max arch:
tuberosities, vibrationg line
This may need to be extended to get the retromolar pad in the retromylohyoid region:
lingual flange, esp for distal extended RDP
Ideal temp for mixing alginate:
70F
Have pt do this while mixing alginate:
rinse with water
How to impress the anterior vestibule an get all anterior teeth:
retract lip when seating tray and drape lip over the tray
TF? Tray should be seated all the way when taking impressions.
F. leave 4-5mm space
How long should the tray set?
3m
Where to apply light pressure while alginate is setting:
L and R premolar areas
Direction to remove the ray:
with the long axis of tooth (to avoid tearing or distortion
Adv of making individual trays:
more accurate tray adaptation, even thickness of material, helps w adjustments of tray extension, border molding procedures, and accurate recording of functional vestibular depth
The outline of the tray on the cast should be __ shorter in the distal extension area
2mm
How many layers of wax on teeth and tissue surfaces to create space for material when making custom trays:
1 over tissue, 2 over teeth
These allow for adequate material space in the custom tray:
ant and pos stops
Type of material we use for custom trays:
VLC resin
Beware of this when making handle for custom tray:
should not interfere w lip
Initial cure time for custom tray:
2m
Second cure duration for custom tray:
5m
How to get border molding more accurate for complete dentures
rim instead of handle
What are we doing to the custom tray we when curing it?
polymerizing
Paint custom tray w this material after initial 2m cure:
air barrier coating
Thickness of custom tray:
2-3mm overall
Are modifications easier to make on the stock tray or custom?
custom
Areas of custom tray most likely in need of trimming:
DB area and area of lingual and sublingual frenum
Adhesive to use for stick compound (modeling plastic?):
none
Areas of mandibular tray to border mold:
lingual border, edentulous areas, for major connectors
Take note of this when taking secondary impression:
height from lingual vestibule to the gingival margin
Material we use for 2’ impressions:
heavy body PVS
start borde molding here:
lingual side, maxillary - tuberosity and posterior region
Don’t forget to do this in areas that you will be placing PVS or border molding
place adhesive on custom tray first
When to block out interproximal area:
if it helps w removal of impression, need for stronger dentate area on the master cast (perio pts), ues soft, sticky peripheral wax
When should you block out PRDP framework area before taking secondary impression?
never
Materials to block out interproximal areas in clinic:
soft periphery wax or oraseal caulking and putty material
TF? Desicate teeth before placing oraseal into interproximal areas.
F. adheres in wet environment
PVS sf:
polyvinyl siloxane
Where to place light body for secondary impression:
stopped at slide #45
