Nitrous oxide is safe for use in children. However, not all children are appropriate candidates for nitrous oxide. Children with behavioral problems or certain medical conditions (e.g., mental retardation) may not be able to respond appropriately while under nitrous oxide sedation. Certain sensations (e.g., euphoria) may intensify in these patients, making them difficult to manage. Parents should advise the dentist about any existing conditions or medications their child may be taking.

Nitrous oxide is primarily used in children over 4 years old because it requires cooperation by the patient. A typical demand-valve mask releases nitrous oxide in response to a patient’s inhalation. Younger children may have difficulty breathing normally with this mask, and thus may receive ineffective administration of the gas. Masks with a continuous-delivery feature (that does not require active participation by the child) may be used to administer nitrous oxide to children under age 4.

Elderly people may be more sensitive to nitrous oxide, which can increase the risk of side effects. Older patients should consult their dentist about whether nitrous oxide is appropriate for them.