I have recent pain on percussion on rct tooth done 8months ago xray took 4weeks ago was normal why? do i have to retreatment or extraction of tooth?

RCT Pain: I would start with my dentist/ endodontist who treated the tooth. Then get a second opinion. Is the rct failing in so short a time, is the tooth cracked, is there a crown on the tooth to protect it, has a canal been missed? Questions you should ask yourself and the treating dentist or the endodontist you get a second opinion from. Let us know how it turns out.

Pain after RCT: It could be a bite problem, unfilled accessory canal, failed root canal treatment, minute root fracture undetectable with 2d x-ray image, coronal fracture or something else. See two endodontists for independent evaluation and consider 3d cbct scan that may show something that 2d scan and visual cannot. I have seen these things pass over time and without the need to retreat or extract.