Autumn Quiz: final impression techinques + provisional 2 Flashcards
what are the cord thicknesses
000, 00, 0, 1, 2, 3
where should the first cord go and what is it for?
BELOW the margin
- for SULCULAR STABILITY.
- prevents blood and crevicular fluid from contaminating the margin
-noo overlapping
what is the second cord packed for
for lateral displacement
- flash?
- remove just before taking impression. we will remove it before taking impression, this is to give us “space” in the gum tissue
what are the 2 types of pvs materials for final impression
heavy body (blue) to load tray
light body (pink) on prep
whats the tray adhesive for
makes sure impression material sticks to the tray..
how long do you seat stock tray on mouth
approximately 5-6 minutes, till pvs is set
what is the working time and the full set time for the pvs material?
working time is 2 minutes
full set is 5 to 6 minutes.
-both heavy and light should set at the same time to blend right
what requirements must be met for the final impression
- exact duplicate of prep, enough FLASH below margin for accurate definition of the margin
- other teeth must accurately be reproduced in order to articulate the casts correctly. NO tray show through
- free of bubbles and voids, especially in area of finish line
- impression material MUST NOT be separated from the tray
why do we want flash
the more flash, the easier ti is to trim the dies during laboratory phase of crown fabrication
how much do we remove on putty at cervical area
2-4 mm (gives leeway when contouring provisional)
what is lubricant used for with provisionals
to lubricate typodont but NOT in real practice?
how long do you leave putty on typodont after seating with resin for provisional
about 1 minute. check consistency w explorer
how do you remove the temp from the typodont
with spoon
how long is the temp kept in the putty after removing it from the typodont
6 minutes (clean typodont while doing this)
how do you use a splint to make a provisional?
first- poke vent holes from INSIDE of splint to allow excess to escape. can also be used with perio probe to ensure occlusal reduction
-load splint with resin, seat, and use same procedure as putty matrix.
what will pinpoint contact do
will cause temp to be less retentive and lead to food impaction
how do you remove air inhibited layer ?
on resins like bis-acrylic and composite
-remove with alcohol on cotton swab for less mess when adjusting the temp?
what does a fracture on provisional indicate
undercut/under tapered, fractures during removal
-under reduced, thin temp- fractures easily
check for thin areas with light
what does an open margin on provisional indicate about prep
if its closed in some areas; it indicates that flash is preventing seating of the temp. or margin opened up when trimming it.
-if open circumferentially, the temp is not fully seated. so first try cleaning it. relieve intaglio with polishing points or fine finishing bur
prep also could be undercut, under tapered or sharp
what can high occlusion of a temp result in?
- fracture of restoration or tooth
- pain/discomfort
- damage to periodontium. can accelerate bone loss in patients with perio disease
what symptoms will come with inflammation of PDL (occlusion caused)
- pain to biting and percussion
- sensitivity to cold
- usually resolves when occlusion is adjusted
what study did filippi/tecco do for rats and malocclusion
-placed composite “bite pad” on upper right molor of rat. took x ray after 1 week. then placed composite on upper left molar, take x ray after another week.
- first week- unbalanced occulsion
- second week- occlusion was REbalanced
how do you remove occulsion marks
with rubbing alcohol on typodonts (ONLY)
how do you clear occlusion marks
with the footballs- red or yellow/
check multiple times, not exact science, use some common sense. if bulls eye (too dark), smear (too light, false occlusion mark)
-check occlusion on ADJACENT teeth toolook for open bites!
