Nitrous Oxide was first discovered by an English cleric named Joseph Priestley in 1774. Later, in 1800, Humphry Davy, an English chemist and physicist, picked up on his work. He subjected himself an animals to the gas and made many observations, most notably, that the gas produced a very pleasant sensation, and reduced the sensitivity to pain. It was not until 1844, that a young Connecticut dentist named Dr. Horace Wells saw a public demonstration of nitrous oxide at a carnival and realized the possibility of using it for dental treatment. The next day, Dr. Wells had nitrous oxide delivered to his office, and had a colleague extract his own infected tooth under the influence of the gas. The results were astonishing, and Dr. Wells continued to use nitrous oxide gas for patient treatment thereafter.
Nitrous oxide is used in roughly one third of dental practices in the United States. The benefits of nitrous oxide are many, and the risks are few. The gas is administered with a comfortable mask placed over the nose, and the patient is instructed to breathe in through the nose and out through their mouth. As a precaution, patients should not eat anything for about two hours prior to use of the gas. The patient begins to feel a pleasant level of sedation in anywhere from 30 seconds to three or four minutes. The cheeks and gums will also begin to feel numb in about a third of the patients.
After the gas is adjusted to the appropriate dose, and the patient is relaxed and sedated, the dentist can comfortably give the injection (if needed) to the patient, and then proceed with dental treatment. After the treatment is completed, the patient is given pure oxygen to breathe for about five minutes, and all the effects of sedation are usually reversed. Unlike IV sedation or general anesthesia, the patient can almost always leave the office by themselves, without an escort.
Nitrous oxide has few side effects. High doses can cause nausea in some patients, and about 10% of patients do not benefit from it. Patients that are claustrophobic or have blocked nasal passages cannot use nitrous oxide effectively. Nitrous oxide is one of the safest anesthetics available. Interestingly, it is also routinely used by anesthesiologists for general anesthesia in combination with other more potent gases.
I use nitrous oxide frequently in my practice. I find it especially useful for fearful patients as well as young children. The effect of nitrous oxide is often remarkable. A patient that was anxious just a minute or two before treatment will become relaxed and calm. Because nitrous oxide is so effective, I rarely need to prescribe Valium for anxious patients before treatment. If you are nervous before or during dental treatment, ask you dentist if he or she has nitrous oxide available, it works wonders!