I went in for a root canal, post, and crown. After it was over, the dentist explained to me that as they were finishing, the tip of the instrument (file?) broke off in the root. He explained that it may be fine, but we may end up having to go back and do a bridge. He said he would take the cost of the root canal off of the bridge. He said its rare but it does happen. Said he hadn't seen it in years. I have been on antibiotics up until about 3 days ago. I haven't had any pain from it, but it felt like it "itched" under the tooth. Tonight, it just started hurting. Went to a part of the pain scale I've never been before. I'm guessing infection is back or something? Just curious if the "breaking" thing was common and if so, was there ever any chance of keeping the post and crown? Thanks.