Nitrous Oxide, commonly known as laughing gas, is a safe, mild sedative. It is has a calming effect on the child so that they can receive treatment safely and comfortably. Your child will remain awake and alert but in a relaxed state. Nitrous Oxide is always delivered mixed with oxygen. Once the gas is turned off, the effects of sedation wear off almost immediately. Once treatment is completed your child will remain on oxygen for 5-10 minutes to help flush the body of any remaining gas.