Laughing gas does not put a child to sleep. That is the main difference between it and a general anaesthetic, and it is a large part of why nitrous oxide has been used so widely in children's dentistry for so long. Your child stays awake, breathes on their own and can talk to the dentist, but feels calmer, lighter and less bothered by what is going on.
For a child who is anxious but able to sit in the chair with some help, it can make a filling or extraction far easier. It is not right for every child, and it works best alongside a patient, unhurried approach rather than instead of one.
What the gas actually does
Nitrous oxide is a colourless gas with a faintly sweet smell. In the dental chair it is always given mixed with a generous amount of oxygen, through a small cushioned piece that sits over the nose. Within a few minutes most children feel relaxed and warm, and some get tingly fingers or a heavy, floaty feeling. Some giggle, which is where the nickname comes from, though plenty do not.
It also takes the edge off discomfort, but it is not a substitute for local anaesthetic. If the tooth needs numbing, that is still done, and children on laughing gas often notice the injection much less.
The gas is not stored in the body to any real extent. It leaves through the lungs, so once the dentist switches the mask to pure oxygen for a few minutes at the end, the effect fades quickly.
Why it is considered a low-risk option
Nitrous oxide sedation has a long track record in children and a wide safety margin when it is given with oxygen by a trained team using equipment that limits how much nitrous can be delivered. Children keep their protective reflexes such as coughing and swallowing, and they do not need the fasting, airway management or recovery time that deeper sedation or a general anaesthetic involves.
Side effects are uncommon and usually minor. The most common is nausea, and occasionally vomiting, which is more likely after a large meal or at higher concentrations. Some children feel briefly light-headed, have a mild headache, or dislike the floaty feeling. These settle soon after the gas is stopped.
Children it may not suit
A child has to breathe through the nose for the gas to work, and accept something resting on their face. That rules out some children:
- very young children, often under about three, who may not tolerate the nose piece or understand what is happening
- a child with a heavy cold, blocked nose, large adenoids or a habit of mouth breathing
- some medical situations, such as recent ear surgery, certain lung conditions, some chemotherapy medicines and rare problems with vitamin B12 metabolism
- children who are extremely distressed or unable to cooperate at all, for whom laughing gas alone is unlikely to be enough
This is why the dentist goes through your child's medical history beforehand. If your child is unwell on the day, the appointment may need to move.
The appointment, step by step
- Before you come. Give a light meal a couple of hours ahead rather than a big one, and follow any specific instructions you are given. Let the team know about medicines, asthma or recent illness.
- Getting used to the mask. Children often pick a scent for the nose piece and practise breathing through it with plain oxygen first.
- Starting the gas. The nitrous is increased gradually until your child seems comfortable, and the dentist keeps adjusting it throughout.
- Treatment. Your child stays awake and can respond. Numbing and treatment go ahead as planned.
- Clearing the gas. At the end, pure oxygen is given for several minutes. Most children are back to themselves within a short time.
Many children can go back to school or normal play the same day, though it is sensible to keep things quiet for the rest of the appointment day and to supervise eating until any numbness wears off.
When laughing gas is not enough
For a child with a lot of treatment, a very young child, or one who cannot manage the chair even with gas, the options shift. That may mean spreading treatment over shorter visits, using preventive care to buy time, or referring for treatment under general anaesthetic in hospital. Please ask us about sedation options if you want to talk through what may suit your child.
Much of what helps anxious children has nothing to do with sedation. Our guide to children's dental anxiety covers preparation and gentle approaches, and families of autistic children may find our page on autism-friendly dental visits useful.
Typical costs in Australia
These are general market ranges to help you plan. They are not Lumi Dental fees and not a quote.
| Item | Typical market range (AUD) |
|---|---|
| Nitrous oxide sedation, per visit | $80 to $200 |
| Child check-up and clean | $120 to $280 |
| Eligible children under the Child Dental Benefits Schedule | Many basic services covered, subject to eligibility and the benefit cap |
Whether the CDBS or private health insurance helps with sedation depends on the item and your cover, so it is worth checking before the visit.
Questions about laughing gas
Will my child remember the appointment?
Usually yes, at least in part. Nitrous oxide is not designed to wipe memory, although some children recall the visit as shorter or vaguer than it was.
Can I stay with my child?
In most cases a parent can stay in the room. The dentist may ask you to sit quietly so your child can focus on their voice.
Is it safe for repeat visits?
For occasional dental appointments, repeat use is routine. Long, very frequent exposure is what raises concern, which is not how it is used in dentistry.
Planning a visit for a nervous child
If your child is due for a first filling or you are worried about how they will cope, book a visit with a general dentist to talk it through first. We can look at the teeth, explain the options and let your child get used to the room without any pressure. Wondering about X-rays as well? Our article on dental X-ray safety for kids covers that. Free consults for nervous patients and other current offers are listed online.
This article is general information and is not a substitute for advice tailored to your child.
