Nitrous Oxide – commonly known as laughing gas – is a safe and highly effective sedative that is used widely in dentistry. Over half of U.S. dentists have nitrous oxide as part of their pain control repertoire, and for many good reasons. When properly applied, it is a safe to use and effective method of controlling anxiety and easing pain during dental procedures.

How does nitrous oxide work?

For nitrous oxide to have the desired effect, it must be mixed with oxygen (usually at least 30%) and inhaled continuously. This colorless, odorless and nonflammable gas works by entering the bloodstream after being inhaled, and almost immediately causes feelings of calmness and relaxation.

When being given nitrous oxide for pain and/or anxiety relief, you are required to wear a mask that delivers the nitrous oxide/oxygen mix. You then take a few deep breaths before breathing normally, and should feel the effects shortly after. These calming effects wear off almost immediately after the mask is removed, making nitrous oxide an incredibly popular choice of sedation.

What can I feel while receiving nitrous oxide?

If you are usually anxious about dental treatment, you will feel comfortable and relaxed before and during the procedure. Because the gas is colorless and odorless, it won’t feel much different to breathing normally – the only difference will be that you are wearing a mask.

It is important to know that nitrous oxide does not put you to sleep, but rather it makes you feel significantly more comfortable about receiving dental treatment.

Are there any side effects?

Although your dentist will have been trained to safely apply the correct amount of nitrous oxide, there are some potential side effects if the nitrous level is too high:


  • Headache
  • Sweating
  • Shivering
  • Fatigue
  • Nausea and/or vomiting


Headaches can usually be avoided by inhaling oxygen for a short while after the nitrous oxide has been turned off. This purges any remaining nitrous from the lungs and aids the patient in returning to a ‘normal’ state.

Certain groups of people, such as pregnant women, should avoid using nitrous oxide. Talk to your dentist about any concerns you may have – they will be happy to talk you through any alternative sedation methods that may be more suitable for you.