Nitrous Oxide (laughing gas) is ALWAYS administered with oxygen. Nitrous oxide is a safe gas and is 100% exhaled by the patient. The combination of nitrous oxide and oxygen, inhaled by your child during the restorative appointment, is used to relax a mildly anxious child. Nitrous Oxide/oxygen also acts to minimize discomfort during dental treatment.Your child does not fall asleep and can effectively communicate with the dentist.Your child should be able to return to normal activities upon leaving the dental office, however limit the amount of physical activity immediately following treatment.