SYNOPSISA woman developed intractable facial pain following the use of N2 paste for endodontic filling. Radiographsrevealed a radiopaque body adjacent to the site of the nerve supplying the painful area, but removal of thisaccumulation of N2 paste failed to relieve the pain, presumably because of leaching of the components of the N2paste into the tissues. Ultimately, nerve avulsion had to be performed to relieve the pain.