Overview
Inhalation sedation for children having dental treatment
Sedation is sometimes given to children during dental treatment to help keep them calm. This can help if they are feeling anxious, worried, or scared about their treatment.
Children can breathe in (inhale) a mixture of oxygen and nitrous oxide gas through a nose mask. This is called inhalation sedation, or ‘happy air’.
This makes your child feel sleepy, and relaxes them physically and mentally. Your child will be awake during treatment, and can talk to the dentist, but it can help them cope with the treatment.
It can also help if your child is scared of injections, or gags during dental checks or treatment.
Having inhalation sedation
Inhalation sedation can usually be given to children from the age of 4 or 5.
- The dentist will place a small mask over your child’s nose, and switch on the inhalation sedation.
- After a few minutes, your child should start to feel more relaxed. They might also feel giggly, have a tingling feeling in their fingers or toes, a warm sensation all over the body, or a feeling of floating.
- The dentist and dental nurse will help put your child at ease by talking softly and calmly during the treatment.
- When the dental treatment is finished, the dentist will turn off the inhalation sedation.
- Your child will breathe oxygen to help them recover, until the sedation medicine wears off. Then the mose mask can be removed.
Your child might still need to have an injection of local anaesthetic during their treatment. This will numb the area, and stop them feeling any pain.
If your child needs local anaesthetic, they will be given this while they are sedated.
If your child has a cold
If your child has a heavy cold, they might not breathe in the gas easily. This can mean they are not completely sedated for their treatment.
For this reason, your child should not have inhalation sedation if they have a heavy cold.
Please call the hospital to rearrange your child’s appointment.
Risks of inhalation sedation
Inhalation sedation is very safe. It has no health risks for patients.
In some cases, children can feel sick (nausea) or be sick (vomit). This does not happen often, but we suggest that they have only a light meal up to 1 hour before their appointment.
Some children feel dizzy, but this feeling goes away after they stop inhaling the gas.
Your child might not like wearing the mask. We can help by showing your child the mask and getting them to practise wearing it before the gas is switched on.
Giving your permission (consent)
It's important for you to be included in decisions about your child’s care and treatment.
If you decide your child should have sedation, you'll be asked to sign a consent form to say that you understand what the treatment involves, and agree for your child to have it.
Other types of sedation
Inhalation sedation might not be right for your child. This can depend on your child’s age, and how well they can understand and cope with the procedure.
Sometimes inhalation sedation is not successful, and a different type of sedation needs to be used, or they might need a general anaesthetic.
Having sedation through an injection into a vein (intravenous sedation) can give a deeper type of sedation.
For some children, a general anaesthetic is needed. This means your child will be asleep (unconscious) for their treatment.
You can talk to your child’s dentist about different types of sedation, and what is best for your child.
Preparing for your child’s inhalation sedation
- Ask your child to practise breathing through their nose with their mouth open. Try this for 10 minutes each day, for 3 or 4 days before the appointment
- Your child can have a light meal and drink up to 1 hour before their appointment.
- Your child will need to come to their appointment with someone who has legal parental responsibility for them. This is usually their parent, but it might be someone else, such as a carer. Please ask us if this is not clear.
- Do not bring other children with you, as your child having treatment will need you to care for them. If you bring other children to the appointment, the appointment might need to be cancelled.
- If you or your child are pregnant, or you think you or your child might be pregnant, please let your dentist know. There is a very small chance that nitrous oxide could harm an unborn child.
After your child’s treatment
Your child should be supervised by a responsible adult (over 18 years of age) for the rest of the day.
It's important that you follow any instructions and advice about caring for your child’s mouth after treatment. Your dentist will give you this information.
You'll be told if your child can return to school on the same day.
Your child should not play any sport for the rest of the day.
They can go back to their usual activities the day after treatment.
You can watch an animation about inhalation sedation, made by the University College London Hospitals NHS Foundation Trust.
Support and more information
University College London Hospitals NHS Foundation Trust have created some animations that you might find helpful.
Paediatric inhalation sedation for dental treatments - for children
Paediatric inhalation sedation for dental treatments - for parents, guardians and carers
Paediatric inhalation sedation for dental treatments - for children, with British Sign Language
Resource number: 4145/VER4
Last reviewed: July 2026
Next review due: July 2029
