A filling was replaced with a large filling (regular silver amalgalm) in back molar #31 tooth about 4 months ago. The tooth had not bothered me at all before filling it, although the dentist said it was a little loose and had some decay. I can't say exactly when it started but soon afterward, the tooth started to bother me when I bite down on it. It's not sensitive to hot or cold and it does not usually hurt if I am not chewing on it. It just hurts a lot when I bite down on it and seems like this is coming from the back area of the tooth. Could the dental procedure have fractured the tooth? What are the possibilities here - fractured tooth or not all the decay was cleaned out or something else going on?