Loose tooth after root canal treatment

My tooth seems to becoming loose and the area above the tooth in the gums has become inflammed possibly turning in to an abscess, no pain at the moment. Has the treatment failed or something, my dental surgeon said it will be extracted if it fails as there was a 50% chance of the tooth actually being saved (the other 50% chance that it would fail). Does it look like my tooth will be extracted?

[scottma]

If root canal is optimally obturated, seeing a periodontist is advised.

[StratRebel]

A tooth becoming loose after a root canal is not normal, and indicates a failure to diagnose or treat correctly.  Three possible causes:

1) Major infection prior to the root canal around the tooth that ate away all the supporting bone.  If this is the case, a root canal should never have been done.

2) Does it feel like you hit that tooth first or harder when you bite down or slide your teeth together right or left?  Problem would be the restoration is too heavy and needs to be ground down to correct the bite.

3) The tooth had bone lose before the root canal due to periodontal disease, and the tooth should never have had a root canal.