jyshrek,

Your root canaled tooth has pain to heat because it is infected and the surrounding area is inflamed and also possibly infected. Not all root canaled teeth will be sensitive to heat but many of them are.

Dental xrays will not show the infection inside of the tooth until the bacteria has spread beyond the tooth and is large enough to be picked up on the 2 dimensional radio graph.

Dentists know that root canaled teeth are not healthy and that the tooth is on borrowed time. The only option to eradicate the infection is to remove the source, which is the tooth. The longer the tooth is present, the more progressive the infection will become. Because your root canal was done within the last year, the infection may not have spread far enough yet to deteriorate the jaw bone. Perhaps you can consult with an oral surgeon about removing this tooth and replacing it with a dental implant.

Bryanna