I have been through root canal for one of my tooth. It was ok when it was done but after two days I got pain there which lasted for 3-4 days and it itself got cured ,I mean without any use any tablets I've got relief from it. It's around 6 months from the date I have done root canal, suddenly it started to pain from yesterday. The outer look of cap was perfect. Pain was uncontrollable even after taking pain killer it's paining after 5 hours. Can any one tell me the reason and precautions, what should be followed.