What is nitrous oxide?

Nitrous oxide, also known as laughing gas, is a mildly sweet smelling gas. Mummies might have used it for some pain control during childbirth! It is also a commonly used mild sedative to help children (and adults) to relax during dental procedures.

How is it used in dental clinics?

Nitrous oxide is given as a mixture of with oxygen which the patient will breathe in (inhale) through a mask placed over his/her nose. The effects of nitrous oxide usually take effect within a few minutes, and they can be adjusted to provide the desired level of sedation. The dentist will monitor the patient continuously to ensure their safety. The effects of nitrous oxide typically wear off quickly after the sedation. It is a safe and effective option for many types of dental procedures, including cleaning, fillings, and extractions.

How would patients usually feel?

Under the mild conscious sedation, patients is awake at all times; they may feel more relaxed and slightly drowsy. They would still be aware of the surroundings and dental procedures. Some may also experience a sense of euphoria or lightheadedness. They may also feel tingling in their hands and/or feet.

Who can benefit from nitrous oxide inhalation sedation?

The indications for using nitrous oxide in dentistry include:

  1. Dental anxiety: Nitrous oxide can help mild-moderately anxious patients feel more relaxed and comfortable during dental procedures.
  2. Gag reflex: Nitrous oxide may reduce gag reflex in patients with strong gag reflex during dental procedures.
  3. Needle phobia: it may help patients with fear of needle to better cope with local anaesthetic injections
  4. Dental procedures can include tooth extractions, fillings, crowns, root canal treatment and so on.

Details are in the following article by Yee et al 2019.

Nitrous oxide mild dental sedation is not suitable for all patients; a dentist trained in sedation should assess the patient’s individual needs, sedation history, behaviour, and medical history before determining if nitrous oxide sedation is an appropriate option.

What are the possible side effects?

Some common side effects include:

  1. Sleepiness: Patients may feel sleepy after the sedation; this usually goes away within a few hours.
  2. Nausea and Vomiting
  3. Dizziness and lightheadedness.
  4. Headache: A mild headache may occur, especially if the patient inhaled high concentrations of nitrous oxide.

Overall, nitrous oxide is considered safe and well-tolerated by children and adults. Most patients experience no or only mild temporary side effects. If you have concerns or unusual symptoms after dental sedation, contact your dentist immediately.


Reference: Yee, R., Wong, DJN., Chay, PL., Wong, VYY., Chng, CK., Hosey, MT. (2019) Nitrous oxide inhalation sedation in dentistry: an overview of its applications and safety profile. Singapore Dent J. 2019;39:1-9. doi: 10.1142/S2214607519500019 Available: https:// www.worldscientific.com/doi/pdf/10.1142/S2214607519500019 [Accessed 09-Sep-2019]


Article contributed by Dr Yee Ruixiang BDS (S’pore), MSc (Paediatric Dentistry)(London), Grad Cert in Advanced Clinical Dental Practice (London), MPaedDent RCS (England), FAMS.