Nitrous oxide (N20) is commonly called "laughing gas." It relieves pain and anxiety during dental procedures. It was first used this way in 1844, when a Connecticut dentist named Dr. Horace Wells tried it on himself while having a tooth extracted.
At first, Wells and others thought nitrous oxide would keep patients pain-free during dental procedures and surgery. However, they discovered it is not a powerful painkiller. Today, it is used in dentistry to relax people. It is also often used in general anesthesia.
Nitrous oxide is a colorless gas with a pleasant taste and odor. People first inhale 100% oxygen through a soft nosepiece or mask. Then, nitrous oxide is slowly mixed in with the oxygen. Nitrous oxide usually starts to work in less than five minutes. Your dentists will adjust the mixture of nitrous oxide and oxygen to a level to ensure your comfort.
When used for mild (conscious) sedation, nitrous oxide may make you feel:
- Happy or silly
You also may feel:
- Tingling in your hands and feet
- Numbness in your mouth, feet or hands
- Heaviness or lightness
- Changes in the way you hear sounds (everything sounds far away or muffled or you may hear a sound described as "white noise")
- A sense that everything is wonderful
- In rare cases, anxiety
Nitrous oxide does not put you to sleep. You can still respond to your dentist's requests and answer questions. Your speech may be slightly slurred, and your responses may be slower than usual. In general, you will be relaxed and cooperative. You will know when you are receiving an injection, and you may even feel it. But you probably won't care. Your breathing and heartbeat will still be normal.
Nitrous oxide is very safe when being used by a properly trained dentist. Ask your dentist about his or her training with nitrous oxide. Side effects may include headache, nausea or vomiting. While you are receiving nitrous oxide, tell your dentist right away about any discomfort or anxiety you feel or concerns you have. You should never be left alone in the dental treatment room when you are receiving nitrous oxide.
If you have side effects, your dentist will turn off the nitrous oxide and allow you to breathe oxygen for up to five minutes. This flushes the nitrous oxide out of your blood.
You should feel normal and alert after breathing the oxygen. However, your motor skills and attention can be affected for as long as 15 minutes after you stop breathing the nitrous oxide. If you leave the dental office sooner than that, ask your dentist if it is okay for you to drive.
People with stuffy noses or breathing problems cannot receive nitrous oxide for dental procedures. The gas enters your lungs through your nasal passages, so these must be clear for the gas to work. Nitrous oxide also is not recommended for people with certain lung conditions. These include emphysema, bronchitis and severe chronic obstructive pulmonary disease (COPD).
Any use of nitrous oxide during pregnancy should occur only after your dentist talks with your obstetrician.
If you take medicine for psychiatric conditions, talk to your physician before receiving any sedatives. If you are a recovering alcoholic or substance abuser, speak with your psychiatrist or drug counselor before you schedule treatment with nitrous oxide. The euphoric feeling that nitrous oxide gives may be harmful to your recovery.
Your dentist may want to talk to your medical doctor before giving you nitrous oxide if you have certain conditions. These include:
- Chronic obstructive pulmonary disease
- Congestive heart failure
- Sickle cell disease
- Ear infection (acute otitis media)
- Recent head injury
- Recent surgery to repair an eardrum
Nitrous oxide is safe for children, but not all children will be able to use it. Children must be able to put up with having the soft nose piece or mask placed over the nose. They also must be able to breathe through the nose, and follow instructions from the dentist.