How to Take Alginate Dental Impressions

Carrington College Instructor Miss Medina shows you how to do dental impressions using aliginate impression material.

Christina Jacobs
This has been a great refresher for me, as impressions/temp.crowns & bridges was my first course at Carrington. And now I am going into ortho where I’ll be taking many impressions lol. Thank you for posting!!

One should not “pack” the powder into the scoop. Rather, fluff the powder in the container before use and lightly level the powder in the scoop.

If she were doing this for a patient post double-jaw surgery for a retainer, the way she is holding the impression would seriously harm the patient. My teeth were horrifically loose post-surgically and if the impression was held with the teeth moved out in the “flared” position (which would happen with how she holds the tray in this video, when it’s drying) my teeth would never heal back in the position they needed to to be in. Finally a superior DDS figured out that this was why my teeth remained loose (to the point of almost falling out). In this scenario, the tray needs to be held firmly INWARD toward the patient’s head, rather than held so that the teeth are being pulled outwards. Even having the patient hold their own tray is optimal (they finally had me do this) as I could feel when my teeth were in the right position vs. being pulled outwards. Even the most minute movement of the teeth being pulled out disrupts EVERYTHING and prevents the teeth and bones from healing after any kind of traumatic surgery. So every time I was putting in my retainer ( a retainer made incorrectly as in this video) and/or removing it, my teeth were being moved and this movement prevented them from healing and stabilizing post-surgically, they always remained loose, vulnerable teeth.

TodaysDentistry ChrisPaterasDDS
A wet paper towel will add water to the alginate causing distortion. The impression should go into a zip lock bag until ready to pour. Fluff the container before scooping alginate. It packs down while it sits and will be denser at the bottom of the container than the top. Level the scoop, don’t pack it.

Edward Dergosits
Alginate (irreversible hydrocolloid) is a great material. Manufacturers market the quickness of the material’s setting time to appeal efficiency. Research done more than 40 years ago demonstrated that the optimal dimensional accuracy is only obtained when the material (all alginate materials) are allowed to set for 3 minutes after the initial set contrary to almost all directions provided with the alginate.Removing an alginate impression from the mouth in 2 minutes is unpredictable in terms of dimensional accuracy. Many years ago I employed a hygienist that wanted to make alginate impressions for fabrication of whitening appliances. The first 6 appliances did not fit well and the impressions were remade by me and new whitening appliances fabricated. The second sets of whitening appliances fit precisely. I tried to explain the problem with early removal of the impression and the hygienist got very defensive and told me she had never had a problem with this before and wanted to blame to poor fit of the appliances on poor fabrication of the vucuformed whitening appliances. When I showed her how accurately the appliances fit to the casts made from her impressions but not in the mouth she said “whatever”. SMH.

I knew I needed an impression done, so I used my throat-numbing cough spray before the appointment, then rinsed like 4 times so the chemical didn’t effect the impression; thanks to that, I didn’t gag everywhere lol