I had a crown put on a broken tooth 10 days ago. I still have an ulcer and quite a bit of pain on the gum under the crown. The novacaine injection hurt terribly, like never before. Could there have been some damage that I still have pain. The office told me to keep gargling with salt water. But after 10 days, the ulcer from what I think was trauma from the instruments is still here. Can this trauma cause an abscess?