Nitrous oxide is used during dental treatment to ease anxiety in patients. It is a slightly sweet-smelling gas that is mixed with oxygen and inhaled by patients through a nosepiece or mask. It is often used in addition to a local anesthetic.

Nitrous oxide promotes mental and physical relaxation, as well as a lessened awareness of pain. Patients receiving nitrous oxide remain awake and responsive to a dentist’s requests. These patients may also experience a tingling or floating sensation, warmth, drowsiness, euphoria, the presence of droning background sounds and decreased motor control. Effects last only as long as the gas remains in the body. After the nitrous oxide is turned off, a patient returns to a fully alert state within minutes.

Nitrous oxide is very safe as long as an adequate concentration of oxygen is delivered simultaneously.

This form of sedation may be used for a wide variety of dental treatments. Its use depends on patient preference more than medical need. It may be recommended for patients with mild to moderate dental anxiety, a hypersensitive gag reflex or cardiac problems. Patients with any form of nasal or respiratory obstruction (including a stuffy nose) should not receive nitrous oxide because nasal passages need to be clear for the sedation to work. In addition, nitrous oxide may not be appropriate for patients with certain medical conditions or under certain circumstances.

If patients receive too much nitrous oxide, they may experience nausea, vomiting and dizziness. Increased sleepiness can lead to unconsciousness. Headaches may occur if a patient does not receive adequate oxygen after the nitrous oxide tank has been turned off. Medications that sedate or depress the central nervous system may interfere with nitrous oxide and can lead to a state of unconsciousness. Patients should inform their dentist about all medications and supplements they are taking.

Nitrous oxide is safe for use in patients of all ages, including children. Elderly patients may be more sensitive to the gas and should consult the dentist about whether nitrous oxide is appropriate for them. Women who are pregnant or breastfeeding should inform the dentist about their condition and any concerns they may have about using nitrous oxide. No conclusive evidence is available regarding its safety to fetuses and breastfeeding children. Generally, nitrous oxide is considered a safe, mild sedative with few side effects.