Because such accidents are rare, the literature lacks precise standardized reporting of risk factors, clinical progression, operator behavior, and treatment following extrusion.
This study reports four cases of NaOCl accidents using 5% solution in maxillary teeth, applying and expanding recently proposed standards for documentation to improve data quality and guide prevention and management.
Case Descriptions
All four patients were treated for canals in maxillary teeth.
Key features shared across the cases: use of 5% NaOCl during irrigation; accidents occurred during final rinsing or irrigation phases; symptoms included intracanal bleeding, swelling of the face/hemiface, ecchymosis (i.e. bruising), sometimes paresthesia.
Treatment involved analgesics, corticosteroids, non-steroidal anti-inflammatories, antibiotics in some cases, and cold or warm compresses.
Symptom resolution was substantial within 5-6 days.
Risk Factors Identified
The study highlighted several anatomic and procedural risk factors:
1. Apical fenestration: In one case confirmed via CBCT; this condition (apex exposed through bone) reduces barrier to soft tissue.
2. Large apical foramina or altered apical anatomy (stripping, apical transportation), lateral canals potentially providing a “portal of exit”.
3. Tooth location: all four cases in maxillary teeth; bone density and thickness of vestibular cortex likely contribute.
4. Operator factors: needle type and its placement, blockage during irrigation, lack of rubber dam in some cases, and possibly decreased attention during later treatment stages.
Treatment & Clinical Outcome
Immediate management: flushing with saline to dilute extruded NaOCl, temporary sealing of the access cavity, application of cold or warm compresses, prescribing pain control (analgesics), anti-inflammatory therapy (NSAIDs, corticosteroids), and, in many cases, antibiotics.
In all cases, symptoms improved significantly by day 5-6; no long-term permanent damage reported.
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Behavior After the Accident & Legal / Ethical Issues
The study documents that clinicians sometimes change their subsequent endodontic protocol: e.g. switching from NaOCl to chlorhexidine as irrigant, adjusting needle type, changing irrigation method.
In one case delayed diagnosis and inadequate initial management led the patient to consider legal action; in others, prompt recognition and adequate management helped maintain patient trust.
Importance of Standardised Reporting
The authors argue for use of a standardized template (building on work by Guivarc’h et al.) to collect detailed and comparable data on NaOCl accidents.
This includes demographic data, anatomical findings (including imaging like CBCT), procedural details (needle size, working lengths, irrigant volume, method), clinical signs and symptoms, timelines, treatment details (both pharmacologic and non-pharmacologic), and medico-legal outcomes.
Such reporting will better clarify risk factors, improve prevention strategies, and offer clearer guidance on managing these events.
Conclusions
While NaOCl accidents are rare, they can cause distressing symptoms.
Key to reducing harm are early diagnosis, timely and appropriate supportive treatment, and preventive measures.
Endodontic treatment should be resumed as soon as possible after accidents, under safe conditions.
The community is encouraged to adopt uniform documentation, which can feed into better evidence, clinical guidelines, and risk management.
💬 I invite the international endodontic/odontological community to READ THE FULL ARTICLE (PDF) to get all the clinical details, images, and standardized documentation template for improving safety in canal treatments.
