Taking an Alginate Impression Flashcards
When determining the amount of alginate material to be used it is best to follow the ______ _____ for the powder/liquid ratio.
manufacturer’s instructions
The most often alginate powder to water ratio is _____ using a plastic scoop.
one-to-one
Before scooping the alginate powder it is essential to _____ the container in order to ____ the alginate material.
tumble; fluff
When making your scoops you will want to _____ the scoop and then ____ it off the spatula.
overfill; level
One thing that you do not want to do is ____ ___ ____ ____ in the scoop.
pack the powder down
The first thing you want to do when before mixing is ___ ____ into the bowl and then add ____.
add water; powder
The two variables that will affect the setting time of the alginate is the _____ ____ and the _____ of the _____.
powder/liquid ratio; temperature of the water
Water that is _____ will set faster and likewise _____ water will set slower.
warmer; cooler
Mixing should be complete within ____. If you increase the mixing time the final product will be _____. If you decrease the mixing time the impression material will become ____.
one minute; stronger; weaker
When mixing is complete the material should appear _____, _____, and free of _____.
smooth; glossy; air bubbles
The removal of alginate is delayed _____ minutes after gelation.
2-3
After the alginate impression has been made it must be _____.
disinfected
The main contributor to the accuracy of the alginate impression is the _____, ______, or ______.
evaporation; syneresis; imbibition
_____: swelling due to absorption of water
imbibition
_______: After hydrocolloids have set they contract as they exude water
Syneresis
When loading the mandibular tray, gather _____ of the material into the spatula and load ____ of the tray from lingual (or buccal) border and press the material ____ and forward. Repeat procedure on the opposing side of the tray.
one-half; one side; downward
Alginate is acceptable for fabricating bridges, crowns, and inlays. Nearly all impression materials are acceptable for full-denture impressions.
a) The first statement is true. The seconds statement is false.
b) The first statement is false. The second statement is true.
c) Both statements are true.
d) both statements are false.
b) The first statement is false. The second statement is true.
What error is in this impression?
a) The tray is too small
b) There is not enough alginate
c) Both a) and b) are possible arrors.
d) There is no error
c) Both a) and b) are possible arrors.
* Solution: Make sure there is wiggle room in the mouth with the chosen tray. Make sure there is enough alginate surrounding all teeth. The problem with this tray is that the alginate has not gone around the second molars*
What error is in this impression?
a) Way too much alginate
b) The mixture has too much water
c) Not clearing out excess in back of the mouth
d) All of the above
d) All of the above
Solution: Use less alginate, check the water/powder ratio, and check to make sure the airway is clear.
What error is in this impression?
a) Not enough alginate
b) Tray is too small
c) Not seated all the way
d) Material started to set
e) Did not move lip over edge of tray
f) all of the above
f) all of the above
* Solution: Fill the tray with enough alfinate, make sure to check tray size for movement, Seat tray until material oozes from lips, do not overmix, bring lip over front of tray.*
What error is in this impression? (Two possible errors)
- The adhesive was not used
- The impression was not kept moist
* Solution: Use adhesive. Disinfect and stor in moist baggie*
What error is this impression?
a) Tray is too small
b) Tray was not centered
c) Impression was not seated all the way
d) Both b and c
d) Both b and c
* Solution: Center the tray as you insert into the mouth. Seat until the vestibules fill with alginate.*
The ideal mix should look like this. It should be smooth and creamy Fills the tray without ____ ____ _____. The tray is not visible under the alginate.
going over edges
The alginate should cover all teeth plus ___ beyond the cervical margin. Name four landmarks that should also be present.
- All vestibules
- Frena are present
- Retromolar pads
- Maxillary tuberosity
- Edentulous ridges
The proper seating of trays is from _____ to _____.
Posterior; anterior
When removing trays, release the suction by placing finger on _____ ____ of the tray and push firmly down for maxillary (up for mandibular)
posterior edge
The process for disinfecting the bite block is rinse with water at the sterilization sink, _____, wrap in paper towel, place in baggie.
spray with disinfectant
Why would the double-pour technique be a preferred method of fabricating a cast/studymodel?
a) It is the quicker of the two
b) Prevents distortion of oral structures.
c) Produces a better reproduction of oral structures
d) It is a safer technique
b) Prevents distortion of oral structures.
* The first pour will have initially set before the second pour is done, which will help prevent distortion*
