medically fit old lady with constant throbbing pain in max 6 since 3 days , the tooth had been rct'd and crowned. pain on vertical percussion . xray showed the roots were filled jst short of apex but no radiolucency . interdental bone loss btw 5 & 6 noted.
Pls share your views on causes and treatment options . thanks

I would suspect a root fracture, high occlusion from crown, residual pain from RCT if done recently, possible RCT failure.