What is "laughing gas" or "nitrous oxide"?

Nitrous oxide (commonly known as "laughing gas") is a safe and effective technique used to calm a child's anxiety of the dental visit. Nitrous oxide is a mix of two gases: oxygen and nitrous oxide. When inhaled, it is absorbed by the body and has a calming effect. Nitrous oxide is perhaps the safest sedative in dentistry since the child remains fully conscious during treatment. At the end of the procedure, nitrous oxide is easily excreted from the body by administering 100% oxygen.