Dental Nitrous Oxide - Laughing Gas
It is known as laughing gas because of its euphoric effects. It is usually a mixture of 50-70% oxygen with no less than 30% nitrous oxide. Laughing gas is delivered to the patient via inhalation mode. It usually produces a calming effect in 2-3 minutes and at the end of the appointment the patient is administered 100% oxygen for 5 minutes to result in complete reversal of its effects.
It is a pleasant smelling colorless gas, with a slightly sweet odor. It is used in dentistry for its anesthetic and analgesic effects. It also relieves dental anxiety and fear, thus making it useful for people with dental phobias and fear of shots or dental "settings. Laughing gas is safe to administer in children as well. Hence making the dental procedure more comfortable and stress free for them. Also due to the mild amnesia caused by the nitrous oxide they usually don't remember most of the procedure.
It is generally observed that people with dental phobias had "bad" dental experience(s) as kids and they retain those fears into their adult life.