Laughing gas is the common term for Nitrous Oxide. It acts as a sedating agent that is mixed with oxygen. During a dental procedure, your child inhales the laughing gas through a small mask that fits over your nose. Laughing gas is used to help a dental patient relax while reducing pain and anxiety during dental treatment. Your child’s dentist may offer to use laughing gas to make him or her more comfortable and at ease during certain dental procedures. Do not worry as kids usually recover quickly from the effects of the laughing gas after their dental treatment has been completed.