I am in the process of having a bridge made but one of the abutment teeth has an ongoing problem that will not go away so I am on my third temporary bridge after various treatments. The tooth has been root filled twice but still I feel discomfort and pain if ever I bite on that tooth. Obviously I try to avoid this but that isn't always possible and the slightest bit of pressure on the tooth (from even by tongue or lips) can set off the discomfort (which is a kind of nagging pressure inside the tooth that can persist all day long). Breathing air over the tooth, hot and cold fluids can all change the feeling inside the tooth. Apparently I should have no sensitivity to hot/cold because the root is dead but can hot/cold/air cause the materials of the temporary bridge to expand/contract differently to the base of the tooth and so cause discomfort? Usually I end up taking pain killers that tend to alleviate the symptoms but only a bit, not completely. My dentist says the tooth is not cracked but what else can be causing pain and discomfort inside a root filled tooth. If I lose the tooth I will not be able to have a bridge at all so effectively one tooth means I will lose five! This I want to avoid if at all possible but what can the problem be and what can I do about it? My dentist suggests the last resort before tooth extraction might be an apiocectomy but how successful will that be? I am not feeling any pain at the tip of the root and there is no swelling - it is all inside the tooth.

Derek,
It might be a good idea to go see an endodontist who specializes in root canals. He may be able to figure out what the problem is. There could be an axillary nerve that can't be detected with the tools your dentist has.