Palate cast
Here are some illustrations of the process of making a dental impression with alginate and then a dental cast from the resulting mold.
The first step of the process is to choose a palate tray. We have three sizes. Select one where the tray does not touch the roof of your mouth
Mix alginate according to instructions on the container. Work quickly, as the alginate sets fast. We find that from the moment you start mixing the alginate until the time it is fully set in your mouth is about three minutes.
For our alginate equal parts water and powder give the right consistency. About 40cc of each yields the right amount for one mold.
Make sure to mix until creamy, then fill the tray. Make sure to completely cover the teeth and palate area of the tray. It helps to put a peak of alginate in the center of the tray to ensure a good impression of the palate.
Bite down on the tray and hold it in place for about a minute and a half.
A successful impression will show detail of the teeth and gums, all the way around the back molars. You will also see the ridges of the palate with no gaps or bubbles.
Keep the mold wrapped in a wet paper towel to keep it from shrinking while you prepare the dental stone to make a cast.
Mix dental stone with water and mix well. The mixture should be thick but flow freely enough to pour.
Pour dental stone mixture into your mold and agitate it on a vibrating plate. Bubbles will emerge from the mixture, and some it will run out of the mold.
Add some more of the stone mixture to cover the top of the mold (the palate area) and set aside to dry. It takes ~20 minutes for the stone to harden enough to be removed from the mold.
The cast will be quite hard when it is ready to remove from the mold. Just pop it out to remove.
Leave the cast overnight to dry out completely before attempting to write on it or measure it.