It's sometimes very difficult to determine exactly what is causing the swelling. I assume you've never had this happen before, i.e the swelling after a dental procedure with anesthetic. Possibilities include; trauma from the injections, some type of allergic response to the temporary material, allergic response to gloves (were they latex ?) or the impression material. The good thing is it will go away. Actually if a shine material was put on the temporaries that was probably the cause and even though it was buffed off, the allergic response had already occurred. The whitish lesions are uncomfortable for sure but they are healing and it will take several days to feel better. Your doctor can probably recommend some OTC remedies to help with the discomfort and prevent your lip from sticking to the temps