Nitrous oxide used for sedating patients during dental appointments has a significant environmental impact, with wide variation in use and wastage across the UK, according to a new UK study.
Inhalation sedation uses a dose of nitrous oxide, otherwise known as laughing gas, and is an established technique for managing dental anxiety in children and adults.
It has a wide margin of safety and is used frequently during procedures such as fillings, crowns and root canals. However, nitrous oxide is also a potent greenhouse gas with a global warming potential 273 times greater than carbon dioxide.
Researchers at the University College London analysed data from 891 episodes of inhalation sedation collected from 31 dental services, covering 128 primary and secondary care sites.
They recorded the average carbon footprint per sedation appointment at 28.6 kilograms of carbon dioxide equivalent (kg CO₂e), equivalent to a 72.8-mile journey in a petrol car.
At service level, the carbon footprint associated with one week of clinical nitrous oxide use ranged from 38.9 to 1849 kg CO₂e, highlighting large variations in practice across the country. The figure of 1849 kg CO₂e would cost the same emissions as 4709 miles driven in a petrol car.
The study, published in the British Dental Journal, is the first to quantify the environmental impact of nitrous oxide use in dentistry across different settings in the UK.
“Nitrous oxide has an important role to play in dental care, particularly for children and young people, but it is also a powerful greenhouse gas,” first author Dr Alexandra Lynem said.
“Our study shows that its environmental impact varies widely between services, largely due to differences in how it is supplied and administered.
“Our recommendations include monitoring use, reducing unnecessary wastage and standardising practice where possible. By doing this, dental services can reduce emissions while maintaining patient care.”
