I had a really sensitive tooth, which turned out to be that my silver filling was cracked. Whenever I brushed, the gum line would hurt, and when I ate sweets, it would also hurt. They said I needed a crown, so I had it done about a 3 weeks ago. Last Monday I went it to have it put on. It hurt really bad when she went to pick at it, so they gave me a shot and it was fine. Then they put the porcilin crown on. Since then, it has been hurting/aching off and on. Is this normal, and how long should this last? Do I need a root canal or something? I'm scared...please help!