Dear practo user Any root canal treatment and crown that was done has to be followed up regularly with your treating dentist. Half yearly visits are mandatory to ensure smooth functioning. The mild pain you mention can be due to several reasons. We cannot assume anything until we see you clinically. Is there food lodgement? Is there sensitivity? Do you have any xrays? Can you send some intraoral pictures? Are you flossing and maintaining oral hygiene? Please contact in our private chat box for further assistance