Nitrous Oxide Sedation — Before, During & After the Procedure

Nitrous oxide is a gas that can be used to help children with small scans or procedures that might be stressful or painful. It is also known as happy gas or laughing gas, and is mixed with oxygen and breathed in through a small mask.

Here is what to expect before, during and afteryour child’s appointment with nitrous oxide sedation. For an introduction to what the gas is and why it helps children, read Nitrous Oxide (Laughing Gas) for Children.

Nitrous oxide masks in three sizes used for children during inhalation sedation
The gas is breathed in through a small mask, available in three sizes to suit every little patient.

Before the Procedure

  • Please give your child a light meal about 2 hours before the procedure.
  • Please ensure your child is well on the day, with no symptoms like cough, fever or a blocked nose — the gas is breathed in through a mask over the nose.

Key Takeaway: A child with a cold or a blocked nose may not be able to breathe the gas properly. Call us ahead to reschedule if your child is unwell.

During the Procedure

  • Your child will feel sleepy and relaxed as they breathe the gas.
  • The gas should not make your child fall asleep — they stay awake and able to respond throughout.
  • The gas will continue to flow until the procedure or scan is finished.
  • Your child’s treating team will then turn off the nitrous oxide but continue giving oxygen through the mask. This helps clear out any remaining nitrous oxide from the lungs.
Child relaxed during dental treatment while breathing nitrous oxide through a mask
Your child is monitored closely by the dental team throughout the appointment.

After the Procedure

  • Your child should be able to return to normal activities immediately, including eating and drinking.
  • Some children will not remember anything about the procedure after having the nitrous oxide gas.

Key Takeaway: Nitrous oxide works quickly and fades just as fast. With a little preparation beforehand, most children leave the clinic feeling completely back to normal.

Prepared by Dr. Lim Siau Peng, Paediatric Dental Specialist. This is general information and is not a substitute for a clinical diagnosis — please ask our team if you have any questions before the appointment.

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