ICD-1 ALGINATE IMPRESSIONS (POURING + TRIMMING)

what is alginate

powder material

irreversible hydrocolloid

regular set alginate

working time 2-3 minutes

setting time 2-3 minutes

fast set alginate

working time 1-2 minutes

setting time 1 minute

alginate particles are composed of

salts of alginic acid (a product of marine kelp)

activator (ex. calcium sulfate)

retarder (ex. sodium phosphate)

inert filler

flavoring

syneresis (dimensional stability)

lose water/dry out

imbibition (dimensional stability)

absorb water

NEVER pour or place these Quickstone substances into a drain without a trap/stopper

stone powder

stone mixture

stone slurry

stone dust

stone pieces

the key to a good impression is the _________________

fit of the tray

what is the purpose of the alginate impression

to accurately record the oral tissues and their spatial relationships

too much to write on (steps for making an impression)

review on study guide

when present with a patient who has a gagging problem

DO NOT directly ask if you are a gagger or if you have a bad gag reflex

distraction methods to use for every patient who could possibly have a gag reflex

wiggle toes

lean forward

do random things (eg. rotate their left wrist)

place salt on the tongue

N2O sedation

topical anesthetic (last resort)

anatomical barriers of good impressions

high vaulted palate / high arched palate / gothic palate (in a sense a v-shaped palate)

mandibular tori

maxillary torus

buccal exostoses

in creating the diagnostic cast, be cautious of

powder to water ratio

1 pouch quick stone + 40 ml of water

surfactant (bubble reducer)

silly putty / paper towel for tongue space (for mand impression)

prior to trimming cast, do these things

never leave a cast in alginate overnight (can cause breakage to occur when attempting to separate impression from the cast)

if not trimming immediately, soak cast in water 5-10 minutes prior to trimming (lengthens lifespan of trimmer; faster; smoother)

what should always be done to the trimmer before beginning to trim?

turn the water on

does temperature affect setting time of alginate

hotter water = faster set time

colder water = slower set time

within how much time should the impression be poured up after being taken

15 minutes

voids in impression

material missing in impression where bubbles had formed

porosities in impression

porous material due to poor mixing of water and material

other potential causes of porosities

lack of surfactant spray

excess water remaining during pour up

holding impression on vibrating plate too long

turning vibrating plate too high

how do you create even base of cast while trimming

keep occlusal plane parallel with wheel