Sodium hypochlorite-related injury with chronic pain sequelae

A 29-year-old woman visited a general dental residency clinic with a complaint of severe aching and burning facial pain with occasional sharp stabbing pain and persistent numbness. The symptoms had been present for seven months after sudden onset during endodontic irrigation with sodium hypchlorite. She was evaluated and treated by one of the authors, who was trained in orofacial pain management.

The patient reported experiencing debilitating symptoms since the hypochlorite injury. She had been treated with methylprednisolone followed by antiseizure, anti-inflammatory and opioid medications prescribed by a neurologist. Examination and testing revealed static and dynamic mechanical allodynia along with neurological deficits on the left side of the face, implicating both peripheral and central pain mechanisms. The orofacial pain clinician made a diagnosis of peripheral painful traumatic trigeminal neuropathy involving all three branches of the left trigeminal nerve. The addition of an oral neurosensory stent and modification of medications reduced the patient's pain, resulting in improved function and quality of life.

Sodium hypochlorite irrigation may lead to injury and persistent neuropathic pain. Diagnosis and management of chronic orofacial pain require an understanding of pain mechanisms and appropriate treatment options. A multidisciplinary approach with clear communication among the general dentist, dental specialists, primary care physician and medical specialists often is necessary.