From Volume 44, Issue 10, November 2017 | Pages 986-987
Aspiration of dental impression material is a rare but potentially serious complication of routine care. Prior to this case report the authors found three other reports of impression material aspiration. The following report describes the presentation, management and sequelae of a case.
Dentists are sensitive to the many risks surrounding their clinical practice. Many of these are predictable and of low impact; reasonably, clinicians warn patients about pain after extraction and root canal treatment. Some risks are unusual, but derive from higher risk procedure and are well described, for example nerve injury with third molar extraction. This report describes the uncommon and morbid sequelae of a low risk procedure, that of impression-taking. General dentists frequently take impressions from one day to the next for the purposes of diagnosis, treatment and monitoring.
This report describes the fatal consequences of impression material aspiration in an elderly male patient.
A 72-year-old male was admitted to a district general hospital intensive care unit after suffering a respiratory arrest at home. This followed a visit to his general dental practitioner where impressions were taken for new dentures. The patient's relative reported that the patient had been supine during the procedure and following this the patient had become short of breath. His previous medical history included frequent chest infections and sleeping in an upright position. His medical records did not include any previous diagnosis of heart or lung problems but his wife gave a history of increasing shortness of breath over the last two years. The patient was a non-smoker and was not taking any medication.
The patient was transferred from a local A&E department and, on presentation, was intubated and being ventilated. A chest x-ray was exposed which revealed extensive pulmonary fibrosis of a chronic nature consistent with post-TB bronchiectasis. An acid-fast bacillus test proved negative. The possibility of foreign body aspiration was raised by the history, and a diagnostic bronchoscopy confirmed a foreign body in the left bronchus (Figure 1).
The foreign body was removed (Figure 2) by rigid bronchoscopy carried out by the critical care team and ENT surgeons. This took around five hours under intravenous sedation. The foreign body was identified as silicone impression material.
The patient made limited progress and continued to be ventilated post-operatively. A tracheostomy was carried out after six days in anticipation of a long weaning period. Repeated attempts at weaning from the ventilator were unsuccessful and his condition did not improve. He passed away on the 33rd day after surgery in respiratory arrest.
Incidence of impression material aspiration is very rare and the authors found only three other reports1,2,3 describing this. Aspiration of foreign bodies is a potentially serious complication of dental treatment. A study from the USA found that more than 2700 people die annually of foreign body aspiration.4 Of these, dental objects are the second most commonly aspirated foreign bodies.
The use of impression materials demands care as their aspiration may be difficult to detect, both clinically and radiographically. Clinicians should give consideration to using impression materials which are radio-opaque and therefore are visible on chest x-ray. Risk factors for aspiration include extremes of age, learning difficulties, medical conditions such as stroke, dementia, Parkinson's disease, and neuromuscular conditions such as cerebral palsy. In this case, compromised pulmonary function may have contributed to aspiration of the impression material.
The possibility of aspirating a foreign body is increased by placing the patient in a supine position. Dentists should, wherever possible, take impressions in an upright position, especially in the patient who may have a compromised airway. Upon removal of impressions, these should routinely be inspected to identify any obviously missing impression material.
Signs of aspiration may include cough, shortness of breath, choking, gagging and inspiratory stridor. If patients are choking, this should be managed immediately with sitting forwards, encouraging coughing, back slaps and abdominal thrusts. Dentists should refer to the Choking Algorithm as set in the Resuscitation Council UK 2015 guidance.5 The same guidance has been adapted for dental aspiration in Figure 3. Immediate referral should be made if aspiration is suspected.
