May JADA discusses calcium hydroxide overfill risk during root canals

Overfill of medication or obturation materials in endodontic treatment can cause permanent neurologic injury, and there are steps clinicians can take to help prevent that, according to an article published in the May issue of The Journal of the American Dental Association.

The cover story, "The Double-Edged Sword of Calcium Hydroxide in Endodontics: Precautions and Preventive Strategies for Extrusion Injuries into Neurovascular Anatomy," looked at five cases where the inappropriate needle application of calcium hydroxide as a disinfectant prior to root canal therapy on a mandibular posterior tooth resulted in significant overfill into the inferior alveolar nerve space.

"Endodontic care and the clinical difficulties in treating the more complex anatomy of molars can especially challenge any practitioner with inherent risks that may not be identified at the inception of treatment," said Dr. Alan H. Gluskin, lead author of the article and professor and vice chair of the department of endodontics at the University of the Pacific Arthur A. Dugoni School of Dentistry. "Often simple and expedient disinfection treatments can become dangerous when applied to posterior teeth. If the neurovascular anatomy is in close proximity to the roots of posterior teeth, the improper use of a needle application of calcium hydroxide medication can produce an outcome of extrusion injury that can have damaging and lifelong neurologic consequences for the patient."

Overfill injuries include both the chemical injury caused by the material and the compressive damage caused by that material entering space meant to be occupied by only the neurovascular anatomy, according to the article. The outcomes can include concurrent pain and numbness, as well as burning pain.

Steps clinicians can take to help avoid overfill injuries include carefully examining radiographs and cone-beam computed tomographic imaging to identify the proximity of neurovascular anatomy to the tooth, enlarging the root canal enough so that the needle does not bind in the canal when injecting, using slow injection and constant outward movement from the canal as the material is injected, and considering alternative applications to needle and syringe, according to the article. If a patient reports postoperative symptoms of pain or numbness, swift intervention is critical.

Other articles in the May issue of JADA discuss dentistry’s social contract, dental outreach programs and current treatment options for dens evaginatus.

Every month, JADA articles are published online at JADA.ADA.org in advance of the print publication.