Sedation (nitrous oxide) for dental procedures

  • Nitrous oxide is a gas, and is commonly known as happy gas or laughing gas. Giving nitrous oxide is a way to help reduce a child's pain and anxiety during dental treatment. The gas is given through a small nosepiece, and your child will be awake throughout the procedure. Children usually recover quickly from the effects of the gas after their dental treatment has been completed.

    Before the procedure

    As the parent or carer, you must give your consent to use sedation and consent for the dental procedure. You need to understand the reasons for sedation and the following risks:

    • In some cases, your child's oxygen levels may drop. If this happens, they will be given oxygen through an oxygen mask. Nurses will carefully check your child's breathing throughout the procedure.
    • Some children may vomit. Very rarely, they may breathe the vomit into their lungs, which may require some specific treatment.


    Your child can have a light meal, such as jelly, soup or toast, and a drink two hours before the procedure. After that, they should have nothing to eat or drink until after the procedure.

    During the procedure

    Nitrous oxide sedation is given in the dental chair. Your child will breathe the sedation gas through a small nosepiece that sits on their nose. It does not cover their mouth.

    • The nitrous oxide makes children feel sleepy and relaxed. Your child will still be aware of what is happening around them, but will feel dreamy and floaty, warm, and have tingling in their hands and feet. They may be a little forgetful, and might not be able to remember the procedure afterwards.
    • While giving the nitrous oxide, staff will monitor your child's level of sedation to ensure that they can still cooperate and follow verbal instructions.
    • The dental treatment will be carried out. Local anaesthesia injections may also be given so that your child doesn't feel pain. These can be given while your child is sedated.

    After the procedure

    Your child will recover from the effects of the nitrous oxide very quickly once their dental treatment has been completed. They will be observed for a brief period following the sedation.

    Some children may feel a little sick or nauseated. If they feel sick or vomit, give your child some water to drink. If they refuse water, try clear liquids, such as diluted fruit juice, or icy poles, jelly or clear soup to help keep your child hydrated.

    If your child has had a local anaesthetic as well, they need to be careful not to bite their lip or cheek while it is numb.

    When to see a doctor

    Contact your treating dentist if your child vomits more than twice in the first hour after treatment, or if you have any questions about their recovery.

    Key points to remember

    • Nitrous oxide gas helps reduce a child's pain and anxiety during dental procedures.
    • You need to give consent before your child has sedation.
    • Children usually recover quickly from the effects of nitrous oxide gas sedation.

    For more information

    Common questions our doctors are asked

    Will nitrous oxide make my child laugh?

    Some people experience a euphoria (intense excitement or happiness) when they receive nitrous oxide, which is why it is often referred to as laughing gas. However, instead of hyping up your child and making them laugh, it is far more likely to calm them and make them quite drowsy.

    What are the alternatives to nitrous oxide?

    Not all children need sedation for dental procedures. Familiarisation visits, distraction techniques and play therapy are helpful alternatives. For some children, sedation may not be effective and other alternatives such as general anaesthesia may need to be considered.

    Developed by The Royal Children's Hospital, Dentistry, Anaesthesia and Pain Management departments. We acknowledge the input of RCH consumers and carers.

    Reviewed July 2018.

    This information is awaiting routine review. Please always seek the most recent advice from a registered and practising clinician.

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