Journal of Restorative Dentistry

: 2014  |  Volume : 2  |  Issue : 2  |  Page : 96--100

A case report of accidental extrusion of sodium hypochlorite into the maxillary sinus during endodontic retreatment and review of current prevention and management

Dominic Peter Laverty 
 Dental Core Trainee in Restorative Dentistry, Primary Care Department, Birmingham Dental Hospital, St Chads Queensway, Birmingham, B4 6NN, United Kingdom

Correspondence Address:
Dominic Peter Laverty
Dental Core Trainee in Restorative Dentistry, Birmingham Dental Hospital, Birmingham
United Kingdom


A case is presented of a patient attending with a sodium hypochlorite (NaOCl) accident of the left maxillary sinus during endodontic retreatment of a maxillary molar tooth. Sodium hypochlorite accidents are relatively uncommon but when they occur there is potential for severe complications. A literature review has been carried out reviewing current recommendations to reduce the likelihood of a sodium hypochlorite accident and the management of a sodium hypochlorite accident if occurs.

How to cite this article:
Laverty DP. A case report of accidental extrusion of sodium hypochlorite into the maxillary sinus during endodontic retreatment and review of current prevention and management.J Res Dent 2014;2:96-100

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Laverty DP. A case report of accidental extrusion of sodium hypochlorite into the maxillary sinus during endodontic retreatment and review of current prevention and management. J Res Dent [serial online] 2014 [cited 2020 May 25 ];2:96-100
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Full Text


Disinfection of a root canal is one of the objectives of root canal treatment. Mechanical preparation will remove many of the micro-organisms in an infected root canal. However, mechanical preparation alone will not be sufficient to ensure a bacteria-free canal and, for this reason, active irrigant is routinely added to the treatment regimen. [1],[2],[3],[4],[5],[6]

Sodium hypochlorite (NaOCl) is a widely used endodontic irrigant in dental practice for endodontic treatment. Although, it is regarded as being safe it has the potential to cause complications. [7] Expression of sodium hypochlorite beyond confines of root canal and its subsequent consequences is known as 'sodium hypochlorite accident' and was first reported in 1974. [1]

This article presents a case report of a patient that had a sodium hypochlorite accident. A review of the literature in preventing or minimizing the risk of a sodium hypochlorite accident and appropriate management is presented to the reader.


A 37-year-old medically fit female patient presented to the Primary Care department with a referral letter from there general dental practitioner (GDP) 2 days after the event due to treatment being carried out during the weekend.

The referral letter was vague but stated that during the endodontic retreatment of the upper left first molar (UL6) there was extrusion of fluid, and that a course of antibiotics and pain relief had been given to the patient and could this patient be managed by ourselves.

On discussion with the patient, they stated that towards the end of endodontic retreatment they felt an immediate excruciating pain on the left hand side of their face accompanied by a blood-stained fluid that came out of the left nostril. The patient stated they were having continuing pain to the left side of the face and associated swelling with occasionally discharge from the left nostril (clear in color).

On clinical examination, it was noted that there was mild swelling and ecchymosis in the infraorbital region [Figure 1], and there was no sensory or motor nerve damage and no eye signs noted.{Figure 1}

Intra-orally, there was no obvious soft tissue abnormality noted. With regard to the dentition, the upper left first molar (UL6) had a temporary restoration and was tender to percussion. The upper second molar (UL7) had cavitated mesial caries that was tender to percussion and had a negative response to vitality testing [Figure 2] and [Figure 3].{Figure 2}{Figure 3}

The dental practice was called to enquire further about the event, the GDP gave further details and stated that whilst carrying out endodontic retreatment on the UL6 during the instrumentation of the palatal canal and irrigating with NaOCl 2% solution, the patient immediately had pain and solution was noted to coming out of the left nostril. The tooth was then temporized and the patient given a course of antibiotics and analgesia (AMOXICILLIN 500 mg TDS for 5 days and IBUPROFEN 400 mg TDS for 5 days) and a referral letter and advised to go to Birmingham Dental Hospital (BDH) on Monday morning.

Radiographic examination (PA UL6,7 and OPT) [Figure 4] and [Figure 5] showed the UL6 had an inadequate root canal filling and associated periapical pathology, the UL7 had deep mesial caries and associated pericapical pathlology. It was also noted there was pneumatization of the maxillary sinus.{Figure 4}{Figure 5}


UL7 - Caries with associated pulpal necrosis and periapical periodontitisUL6 - Inadequate root canal treatment with associated periapical periodontitisSodium Hypochlorite accident of the left maxillary sinus and the peri-radicular tissues of the UL6.

Treatment plan

Urgent Referral to Ear, Nose and Throat (ENT)-acute sinusitis left maxillary sinus due to chemical insultReview patient in 1 week time at BDH and plan further treatment.

As the patient presented 2 days after the event and was on an appropriate course of antibiotics, no further antibiotics were required; the patient was on appropriate analgesia and steroids not given initially due to the delayed presentation of the patient.

The patient was reviewed by ENT that day as an outpatient and had a nasoscopy carried out and given a course of oral steroids, antibiotics, nasal steroids and a nasal decongestant (Nasal VISTAMETHASONE (Betamethasone sodium phosphate) TDS for 7 days, Oral PREDISOLONE 30 mg OD 7 days, CO-AMOXICLAV 625 mg TDS for 7 days and OTRIVINE (Xylometazoline hydrochloride) and Nasal decongestant TDS for 7 days).

The patient was then reviewed 5 days later by ENT and had a further nasoscopy, which showed improvement and no further follow-up was required.

The patient was reviewed 1 week later in BDH and the associated pain, swelling and bruising was much improved and had settled [Figure 6].{Figure 6}

It was discussed with the patient that both the UL6 and UL7 had a poor prognosis and that the UL7 - would require either endodontic treatment or extraction and that the UL6 would require either endodontic retreatment or extraction. If extraction was the preferred option, it was discussed with the patient that there would be a high risk of oroantral communication and thus would need some form of soft tissue advancement procedure.

The UL6 was extracted with buccal advancement flap due to the presence of an oroantral communication which has healed well without incident and the patient is currently undergoing root canal treatment of the UL7 with their GDP.


The objectives of an irrigant in endodontics (as defined by the European Society of Endodontology) are to: Eliminate microorganisms, flush out debris, lubricate root canal instruments and dissolve organic debris. The irrigant solution should preferably have disinfectant and organic debris dissolving properties, whilst not irritating the periradicular tissues. The irrigant solution should be delivered in copious amounts to the canal as far as possible, without risking extrusion beyond the foramen. [8]

Sodium hypochlorite is considered the most effective irrigant, as it is an effective antimicrobial and dissolves organic debris, [9] but has been shown to have less of an ability to eliminate Enterococcus fecalis. [10]

Sodium hypochlorite is tissue cytotoxic [11],[12] and is an effective solvent of both necrotic and vital tissues. [13] When it comes into contact with vital tissue, its causes hemolysis, ulceration, inhibits neutrophil migration and damages endothelial and fibroblast cells. [12] It also affects the vascular permeability not only by directly damaging the vessels but also causing release of chemical mediators. Thus, interstitial hemorrhage is a common complication from extravasation, which causes immediate swelling and severe bleeding. [14]

It has been shown that contact between the periapical tissues and the irrigant cannot be avoided completely. [15] Therefore, careful use is required to ensure that sodium hypochlorite is prevented from entering the surrounding tissues.

Most complications of the use of sodium hypochlorite appear to be a result of its inadvertent extrusion of the solution from the apical foramen, accessory canals or perforations into the periapical tissues beyond the root apex, which can cause violent tissue reactions (hypochlorite accident). [16],[17]

There have been a number of report cases of sodium hypochlorite being injected into the maxillary sinus. [18],[19],[20]

In this case during the endodontic retreatment in preparation of the palatal canal by the general dental practitioner, there has been a communication created between the tooth and the maxillary sinus which has either been created by an iatrogenic perforation or the canal has been prepared to the apical foramen.

There is a close anatomical relationship of the maxillary sinus and the roots of the posterior maxillary teeth. There is usually alveolar bone and sinus membrane that separates the apices of the teeth and the maxillary sinus but this may be thin or even absent (pneumatization) and tends to occur with increasing age. [21]

As the sodium hypochlorite solution was used it extruded into the left maxillary sinus and into the middle meatus of the nasal cavity via the hiatus semilunaris and thus discharging out of the left nostril.

Sodium hypochlorite in the maxillary sinus that will lead to acute sinusitis, and associated bleeding into the interstitial tissues results in swelling and ecchymosis of the surrounding mucosa and possibly the facial skin and may include the formation of a hematoma. [11],[12],[22]

Precautions/prevention of a sodium hypochlorite accident

Always place rubber dam [7],[24] Careful use of sodium hypochlorite [7],[22],[23],[24] Use of lower concentrations of sodium hypochlorite (1-2%) [23] Have an idea of the length and integrity of root canal system before irrigating. E.g. open apex, perforation [11] Use a luer-luk (side-vented needle) device (at least 2 mm short of working length) to avoid the needle dislodging in use and to minimize risk of accidental extrusion into the apical tissues via the apical foramen [7],[24],[25] Ensure syringe does not get lodged within the canal [7],[23],[24],[25] Using low pressure in delivering sodium hypochlorite. [7],[23],[24]

Management of sodium hypochlorite accident

The most important part of management is to prevent further spread of the solution in the tissues and thus minimize tissue damage.

Stop treatment immediately and explain the situation to the patient [26],[28] No further irrigation of the canal as this could cause the sodium hypochlorite to spread further into the vital tissues and cause further problems [28] Removal as much sodium hypochlorite from tooth via an empty syringe to aspirate or use of paper points [28] Dress tooth with non-setting calcium hydroxide [28] Administer steroids (e.g. Intra-muscular 100 mg HYDROCORTISONE NA SUCCINATE) should be administered immediately [12],[26],[28]Oral antibiotics should be taken immediately and continued for 3 days. [12],[13],[26],[27],[28] AMOXICILLIN 250 mg TDS or METRONIDAZLE 200 mg TDS (in a penicillin allergic patient) [7]Appropriate analgesia prescribed [7],[13],[14],[28] The patient should be under review for the next few hours to monitor the swelling [28] The patient should be reviewed the next day and regularly thereafter [14],[28] Patient advised if any increase in swelling or there are any concerns or problems to go to local maxillofacial unit via Accident and Emergency and may need admission Immediate Referral to the local Maxillofacial department should be considered if: [26],[28] Swelling - rapid increase or sizeable swelling [28] Circumstances of patient e.g. elderly patient, complex medical history, immunocompromised, lives alone etc. [28]


This case report highlights the potential risks associated with using sodium hypochlorite as an irrigant during endodontic treatment and the potential need for discussion with other specialities. An effective technique to minimize the potential risk of a sodium hypochlorite accident is a central aspect of treatment. Dealing with a sodium hypochlorite can be stressful and challenging and appropriate management of such event needs to be administered.


1Becker GL, Cohen S, Borer R. The sequelae of accidentally injecting sodium hypochlorite beyond the root apex. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1974;38:633-8.
2Hülsmann M, Stryga F. Comparison of root canal preparation using different automated devices and hand instrumentation. J Endod 1993;19:141-5.
3Hülsmann M, Schade M, Schäfers F. A comparative study of root canal preparation with HERO 642 and Quantec SC rotary NiTi instruments. Int Endod J 2001;34:538-46.
4Hülsmann M, Gressmann G, Schäfers F. A comparative study of root canal preparation using FlexMaster and HERO 642 rotary NiTi instruments. Int Endod J 2003;36:358-66.
5Versümer J, Hülsmann M, Schäfers F. A comparative study of root canal preparation using ProFile. 04 and Lightspeed rotary NiTi instruments. Int Endod J 2002;35:37-46.
6Hülsmann M, Herbst U, Schäfers F. Comparative study of rootcanal preparation using Lightspeed and Quantec SC rotary NiTi instruments. Int Endod J 2003;36:748-56.
7Spencer HR, Ike V, Brennan PA. Review: The use of sodium hypochlorite in endodontics-potential complications and their management. Br Dent J 2007;202:555-9.
8Consensus report of the European Society of Endodontology on quality guidelines for endodontic treatment. Int Endod J 1994;27:115-24.
9Carrotte P. Endodontics: Part 7 Preparing the root canal. Br Dent J 2004;197:603-13.
10Estrela C, Silva JA, de Alencar AH, Leles CR, Decurcio DA. Efficacy of sodium hypochlorite and chlorhexidine against Enterococcus faecalis: A systematic review. J Appl Oral Sci 2008;16:364-8.
11Gernhardt CR, Eppendorf K, Kozlowski A, Brandt M. Toxicity of concentrated sodium hypochlorite used an endondontic irrigant. Int Endod J 2004;37:272-80.
12Gatot A, Arbelle J, Leiberman A, Yanai-Inbar I. Effects of sodium hypochlorite on soft tissues after its inadvernetet injection beyond the root apex. J Endod 1991;17:573-4.
13Becking AG. Complications in the use of sodium hypochlorite during endodontic treatment. Oral Surg Oral Med Oral Pathol 1991;71:346-8.
14Hales JJ, Jackson CR, Everett AP, Moore SH. Treatment protocol for the management of a sodium hypochlorite accident during endodontic therapy. Gen Dent 2001;49:278-81.
15Vande-Visse JE, Brilliant JD. Effect of irrigation on the production of extruded material at the root apex during instrumentation. J Endod 1975;1:243-6.
16Mehdipour O, Kleier DJ, Averbach RE. Anatomy of sodium hypochlorite accidents. Compend Contin Educ Dent 2007;28:544-6, 548, 550.
17Mohammadi Z. Sodium hypochlorite in endodontics: An update review. Int Dent J 2008;58:329-41.
18Kavanagh CP, Taylor J. Inadvertent injection of sodium hypochlorite into the maxillary sinus. Br Dent J 1998;185:336-7.
19Zairi A, Lambrianidis T. Accidental extrusion of sodium hypochlorite into the maxillary sinus. Quintessence Int 2008;39:745-8.
20Ehrich DG, Brian JD, Walker WA. Sodium hypochlorite accident: Inadvertent injection into the maxillary sinus. J Endod 1993;19:180-2.
21Hauman CH, Chandler NP, Tong DC. Endodontic implications of the maxillary sinus: A review. Int Endod J 2002;35:127-41.
22Mehra P, Clancy C, Wu J. Formation of a facial hematoma during endodontic therapy. J Am Dent Assoc 2000;131:67-71.
23Hülsman M, Hahn W. Complications during root canal irrigation-literature review and case reports. Int Endod J 2000;33:186-93.
24Doherty MA, Thomas MB, Dummer PM. Sodium hypochlorite accident a complication of poor access cavity design. Dent Update 2009;36:7-8, 10-12.
25Bradford CE, Eleazer PD, Downs KE, Scheetz JP. Apical pressures developed by needles for canal irrigation. J Endod 2002;28:333-5.
26Witton R, Brennan PA. Severe tissue damage and neurological deficit following extravasation of sodium hypochlorite solution during routine endodontic treatment. Br Dent J 2005;198:749-50.
27Scully C, Ng YL, Gulabivala K. Systemic complication due to endodontic manipulation. Endodont Topics 2003;4:60-8.
28Baldwin VE, Jarad D, Balmer C, Mair LH. Inadvertent injection of sodium hypochlorite into the periradicular tissues during root canal treatment. Dent Update 2009;36:14-6, 19.