We're finally starting some "dentistry!" We began the semester by taking alginate impressions on our dentaforms, then moving on to taking them on each other.
To take the impression, you first select trays that will fit the maxillary and mandibular arches. Then you measure out the impression material (we use alginate), add water, and mix. Then you load the material onto the tray and press it onto the dentaform, holding it in place until the material sets (about 3 minutes because we're not using fast-set). I found it easiest to rub some alginate over all the surfaces of the teeth, really pressing it into the occlusal surfaces, before placing the tray. I tried it both ways, and this seemed to prevent a lot of bubbles from forming.
Then to pour them up, you mix powdered stone with water, mix it with a vacuum-mixer, and pour it into the alginate mold while holding it on a vibrating pad to work any air-bubbles out. After a few attempts and making a huge mess, a classmate suggested I try wrapping my impression in boxing wax, in order to build a solid stone base without it oozing all over the place. Then you wait about 30 minutes for the stone to harden before trimming your cast. Next week we'll start mounting them.
Also in occlusion class, we learned to do intra-oral exams on each other. This consisted of noting any tooth, jaw, or musculature pain, and making a "diagnosis" for what the issue might be. We also took the above impressions on each other, and mounted them to the exact replica of each other's jaw alignment, using a series of instruments to measure alignment of the teeth and jaw while in the most anatomically stable position.
We finally get to drill! We first practiced by drilling shapes into a block, practicing making parallel, convergent, and divergent margins. Then graduated to working on our dentaforms and mannequins.
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