Nitrous oxide in dentistry - Laughing gas

Nitrous oxide is usually referred to as laughing gas. It will relive pain and anxiety during medical treatment. This was first used in 1844 when Horace Wells, a dentist from Connecticut, tried it on himself when he got his tooth extracted. Wells and other experts thought that nitrous oxide could keep patients free from pain during dental procedures and surgery although nitrous oxide is not an effective pain killer. Nowadays, nitrous oxide is used to help people relax. It can also allow other anaesthetics to work better.

Nitrous oxide is a colourless gas that has a pleasing taste and odour. Before a dosage of nitrous oxide, people will inhale one hundred percent of oxygen through a mask or through a soft nosepiece. Afterwards, the nitrous oxide is combined with oxygen. Dentists normally have a mixture that is composed of about one fourth of nitrous oxide and three fourths of oxygen. Nitrous oxide usually takes effect in about five minutes. When nitrous oxide is used for mild sedation, you will feel

  • relaxed
  • warm
  • pleasant
  • tingling sensations in your hands and in your feet
  • numbness in your mouth, feet, and hands
  • heaviness or lightness
  • changes in the way you hear sounds like everything will sound like they are far away
  • sleepiness
  • drowsiness
  • a sense that everything is wonderful
  • nausea
  • in very rare cases, people will feel anxious


Nitrous oxide will not put you to sleep and you will still be able to respond to your dentist’s questions and requests. Your may slur when you speak and you may take longer than usual to respond. In general, you will be very cooperative and relaxed. You will know when you are getting injected and there are times where you may even feel the injection. You will not care anyway and your breathing and heart beat will remain stable and normal.

Nitrous oxide is safe although some side effects may include headache, vomiting, or nausea. When you receive nitrous oxide, you should tell your dentist about any discomfort or any concerns that you may have. If there are side effects then you should tell your dentist about them as soon as possible. The nitrous oxide will be turned off and you will be allowed to breathe oxygen for five minutes. This will flush out the nitrous oxide from your system.

You should feel normal and alert when the mask is removed although your motor skills and your attention could be affected for as long as fifteen minutes. If you are leaving the dentist’s office sooner than fifteen minutes then you should ask your dentist if it is okay to drive.

If you have a stuffy nose or if you have trouble breathing then you should not receive nitrous oxide. The gas will enter your lungs through the nasal passages so they must be clear in order for the nitrous oxide to work. Nitrous oxide is also not recommended for people with lung conditions like emphysema, chronic obstructive pulmonary disease or COPD, and bronchitis.

If you are pregnant then you and your dentist must talk to the physician before taking nitrous oxide. If you are taking medications for psychiatric conditions then you and your dentist must talk to your doctor before getting any sedatives.

Nitrous oxide is safe for children although not all children may be able to use it. Children must be able to keep up with plastic tubes placed in their nostrils and they must be able to breathe through their nose consistently. Moreover, any other instructions from the dentist have to be followed.