Sometimes, after root canal treatment and capping, sensitivity occurs in the adjacent teeth. The sensitivity you feel is probably in the tooth in front or behind the treated tooth.

Please get an X-ray done. Sensitivity could be coming from an adjacent tooth. Root canaled teeth will not show sensitivity

Hello sir, if you get your sensitivity after the rct and caping can only be caused by the gums, because of your oral hygiene care or maintainance. Or could be of a gap between your cap and the gums which can cause infection again in that particular tooth. it's is better to meet your dentist and get your checkup done because follow up is important.