PERIAPICAL NEURAL CHANGES AFTER PULPECTOMY

Pulpectomy and pulpal necrosis result in severance of the nerves that supply the pulp as well as loss of their target organ. Inflammatory ch anges commonly extend into the periapical region to involve those nerv es. The neural response to pulpal loss combined with periapical inflam mation is a derangement oi the periodontal plexus normally located in the center of the periodontal space around the apical third of the roo t; the result is the formation oi a disorganized group of sprouting an d branching axons that have some features in common with neuromas, The inflammatory and neural responses continue for at least a year even w hen pulpectomy is followed by canal debridement and obturation. Then t he responses are reduced but not eliminated by steroids. Root canal th erapy with techniques that do not leave residual inflammation still re sults in increased periapical innervation; the increase seems to be an organized addition to the normal periradicular plexus.