Emergency multidisciplinary management of a sodium hypochlorite injury in an adolescent: Case Report

Case presentation

A 16-year-old male, otherwise fit and well with an allergy to penicillin, was referred to the oral and maxillofacial surgical (OMFS) on-call team by the emergency department of a different hospital 36 hours following extirpation of his upper left second incisor (UL2). The cause of the pre-existing lesion of the UL2 is unknown, but is likely to have been due to dental trauma. The patient attended hospital in pain with significant left-sided facial swelling, extra-oral ecchymosis, peri-orbital oedema and intra-oral ulceration. Prior to treatment the patient had been experiencing significant pain from the causative tooth for several months. Extirpation was performed by an emergency private dentist, using sodium hypochlorite as an irrigant, without the use of dental dam. Immediately following the procedure, the patient reported pain and intra-oral ulceration, with progressive facial swelling occurring the following morning. The patient had contacted the dental practitioner, but was unable to be reviewed by a dentist for a further week, owing to a lack of available appointments.

Clinical examination

On examination the patient was able to maintain his own airway with a respiratory rate of 15/minute and oxygen saturation of 99% on room air. Extra-orally, he had fluctuant left-sided facial and labial bruising and swelling that was erythematous and tender on palpation (Figure 1). Left peri-orbital swelling was associated with significant epiphora and subjective burning sensation of the left eye. He had no visual disturbances and free range of eye movements. Intra-orally there was ulceration affecting the upper left labial and gingival mucosa. He was otherwise apyrexial with a blood pressure of 132/75.

Investigations and results

An orthopantomogram (OPG) (Figure 2) was taken as a baseline to assess the dentition involved and for any obvious apical pathology.

A CT of his facial bones and neck was used to further assess the extent of injury and to assess for any bony infiltration, soft tissue collections, haematomas or presence of surgical emphysema (air) (Figure 3). CT demonstrated a linear radiolucency within the UL2, with extensive subcutaneous oedema and inflammatory fat stranding involving the soft tissues just inferior to the left maxilla and extending to the superior alveolar ridge with multiple locules of gas within the subcutaneous tissues. There was no associated organized collection or changes in the appearance of the underlying bone.

Management

Following clinical assessment and investigations, the patient was admitted under the care of the OMFS team for 3 days for coordinated management of his NaOCl-related facial injuries by the MDT. The patient was treated with 300 mg intravenous (IV) clindamycin every 6 hours, alongside IV paracetamol and two doses of 8-mg IV dexamethasone. Facial cooling therapy using the Hilotherm system (Hilotherm GmbH, Switzerland) was used for controlled, continuous cooling of the facial soft tissues to help reduce swelling by vasoconstriction, and provide pain relief. The left eye was initially flushed with 500 ml of sterile saline and monitored for signs of improvement.

Occular symptoms were managed by the ophthalmology team who prescribed topical 0.2% carbomer gel to the left eye as needed. After the patient declined dilation of the eye, in the context of clinical improvement, he was discharged from their care.

The temporary restoration of the UL2 was removed by the acute dental care department, and the canal flushed with copious amounts of sterile saline to dilute the NaOCl and neutralize the alkalinity of the NaOCl, preventing further cytotoxicity of tissues. Following treatment, the patient reported significant improvement and was discharged home with analgesia and 300 mg oral clindamycin to be taken four times daily for a further 7 days (Figure 4). Subsequent review of the patient 1 week later in the outpatient department demonstrated evidence of continued clinical resolution and improvement, allowing discharge of the patient back to the community.

Discussion

During extirpation, endodontic irrigants are used as antimicrobial agents and to dissolve pulpal tissue. Sodium hypochlorite (NaOCl) is considered the gold standard and most widely used irrigant owing to its antimicrobial and saponification properties, and its ability to dissolve both vital and necrotic pulpal tissue.² However, if it extrudes beyond the root canal system into the peri-radicular tissues, its cytotoxic activity can lead to ‘rapid haemolysis and ulceration, inhibition of neutrophil migration and destruction of endothelial and fibroblast cells’.³ This is known as an a NaOCl incident. The severity of the incident depends on the duration of exposure and concentration of NaOCl used. However, even a small amount of extrusion of NaOCl can result in peri-radicular inflammation. Shetty et al reported that the majority of NaOCl incidents occurred when 3% NaOCl was used.⁴ Further research is required to investigate whether a safe concentration of NaOCl exists.

Risk factors that increase the probability of sodium hypochlorite incidents include:

Kleier et al reported a higher incidence of NaOCl injury in the maxilla compared to the mandible (P<0.0001) and affecting more posterior teeth than anterior ones (P>0.0001)⁶ owing to the low cortical bone thickness and high trabecular bone tissue. Additionally, females were more likely to experience NaOCl incidents than males.⁶ It has been hypothesized that this may be due to the increased bone density in the male population; however, there is a lack of high-quality scientific evidence to support this gender predilection.

Multiple authors^5,7,8 have suggested the use of prophylactic antibiotic therapy to prevent the proliferation of bacteria in the peri-apical space containing necrotic tissue leading to secondary infection. However, Motta et al reported that antibiotics should only be administered if there is clinical evidence of wound infection or exposure.⁹ Simple analgesia such as 1000 mg paracetamol four times daily is recommended to manage mild to moderate pain.¹⁰ Aspirin and non-steroidal analgesia should not be used as first stage pain management owing to the presence of interstitial haemorrhage in the soft tissue.¹¹ Steroid therapy can be used in severe injuries, such as the case described, to control the inflammatory reaction;^8,12,13 however, the effectiveness of this is yet to be established. The use of a cold compress for the initial 24-hour period is advised to reduce oedema, inflammation and pain followed by warm compression for the next 24 hours.¹²Table 1 outlines recommendations on how to manage a NaOCl extrusion incident in a dental practice. It imperative that the patient is reassured and the incident documented in a comprehensive manner.

The majority of patients are expected to make a full recovery; however, the time period of this grossly depends on the extent of injury and the time taken for presentation and commencement of management.

There is a lack of evidence to suggest that endodontic treatment cannot be completed following a NaOCl incident. However, it is highly recommended that irrigants such as sterile saline or 0.2–2% chlorhexidine gluconate are used.^14,15,16

Conclusion

This case highlights the potentially hazardous complications of NaOCl incidents, their clinical presentation and the importance of early recognition and management by an appropriate MDT. It is imperative that clinicians are aware of the clinical presentation of a NaOCl incident and have a system in place to review patients who may be experiencing a suspected NaOCl extrusion. Although rare, these incidents can lead to airway compromise, paraesthesia and widespread tissue necrosis. As such, it is strongly advised that appropriate precautions are in place when using NaOCl to minimize the risk of NaOCl extrusion. This ensures that both clinicians and patients are informed of the risks of using NaOCl as an irrigant during extirpation, allowing both informed consent and appropriate managements of NaOCl incidents should they occur.