Mechanism and clinical aspects of sodium hypochlorite accidents: A narrative review

Sodium hypochlorite (NaOCl) solution is a widely used irrigant in endodontics. However, it is highly cytotoxic and can have destructive effects on surrounding tissues when it is not confined to the root canal during irrigation. The extrusion of NaOCl beyond the confines of the root canal into the surrounding tissues or anatomical spaces is known as a NaOCl accident. The NaOCl accident is a serious iatrogenic mishap that can lead to severe tissue damage and complications, which can be life-threatening and/or cause long-term or permanent consequences with medico-legal implications. Therefore, this narrative review was conducted to provide clinicians with a comprehensive understanding of the mechanism and clinical aspects of NaOCl accidents. A literature search was conducted in various online databases using specific Medical Subject Headings (MeSH) and key search terms. The review included all categories of articles dealing with the NaOCl accident and available as full text. Additionally, a manual method of search was conducted by screening references of the included articles. Duplicate articles and articles available only as abstracts were excluded from the review. The included articles were reviewed, analyzed and discussed according to the following sections: causative factors; mechanism; clinical categorization; clinical manifestations; diagnosis, including history, clinical assessment and examination, clinical investigation, and differential diagnoses; and treatment planning of NaOCl accidents. This would enable clinicians to recognize and manage NaOCl accidents in the best possible manner and minimize their serious consequences. Future research should prioritize the identification of solutions or measures to address the challenges associated with conducting clinical or in vivo studies on NaOCl irrigation and extrusion.