When you have tooth decay or gum disease, you can get infection deeply within the tooth or gum. This infection is an abscessed tooth and can be very painful. Don't neglect as soon as possible you can go to your dentist.
Visit your dentist as soon as possible. He will suggest you proper treatments. You can visit clinic like Dentzz for better assistance.
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.
If root canal is optimally obturated, seeing a periodontist is advised.