Reviewer comment: This eSEA has a comprehensive description of the event. Following the event, the author fully investigated this including searching literature for information. This confirmed the use of appropriate equipment and materials. The report shows good reflection about operator technique, identifies a learning need and has a good action plan. The new patient information sheet is attached as an annex. This eSEA contains useful information for dentists about using hypochlorite during root canal therapy and the management of a patient following an unintended extrusion of hypochlorite during root canal treatment.