The environmental impact of nitrous oxide inhalation sedation appointments and equipment used in dentistry.

Purpose: This paper reports a life cycle impact assessment (LCIA) to calculate the environmental footprint of a dental appointment using N₂O, comparing single-use equipment with reusable equipment. Nitrous oxide (N₂O) is used successfully in dentistry to provide sedation and pain relief to anxious patients, most commonly in children. However, N₂O is a powerful climate pollutant 298 times more damaging than carbon dioxide over a 100-year estimate.

Methods: The functional unit chosen for this LCIA was 30 min delivery of N₂O to oxygen in a 50:50 ratio at 6 L per minute flow rate as inhalation sedation to one patient. Two types of equipment were compared to deliver the anaesthetic gas: reusable and disposable items.

Results: The use of disposable equipment for N₂O sedation produces a significantly larger environmental impact across nearly all of the environmental impact scores, but the overall global warming potential is comparable for both types of equipment due to the vast environmental pollution from N₂O itself.

Conclusion: N₂O sedation is a reliable treatment adjunct but contributes to climate change. Single-use equipment has a further deleterious effect on the environment, though this is small compared to the overall impact of N₂O. Dental priorities should be to deliver safe and effective care to patients that protects staff, minimises waste and mitigates impact on the environment alongside promoting research into alternatives.