Nitrous oxide, often called “laughing gas,” is a compound commonly used in dentistry today to manage patient anxiety and provide pain relief. This colorless, slightly sweet-smelling gas is administered through a mask, inducing conscious sedation where the patient remains responsive but relaxed. The journey of nitrous oxide from a chemical curiosity to a widely accepted dental tool is a fascinating historical narrative, beginning with its discovery and leading to its first application in a dental chair.
Early Scientific Exploration of Nitrous Oxide
The compound was first identified in 1772 by the English chemist Joseph Priestley. Priestley referred to the substance as “phlogisticated nitrous air” and described it as being colorless and sweet-smelling. However, Priestley did not explore the physiological effects of the gas on the human body.
It was Humphry Davy, a prominent British chemist, who revived interest in the gas at the end of the 18th century while working at the Pneumatic Institution in Bristol. Davy experimented extensively on himself, meticulously recording the effects of inhaling pure nitrous oxide, which he noted produced a feeling of giddiness and pleasure. He soon coined the term “laughing gas” after observing the euphoric and often uncontrollable reactions of those who inhaled it.
Davy organized public demonstrations where participants inhaled the gas for entertainment, leading to the phenomenon of “laughing gas parties” among the upper classes. For the next four decades, the primary use of the gas remained recreational, featured in traveling medicine shows and public spectacles. Although its intoxicating effects were well-known, its serious medical potential was largely overlooked during this period.
The Transition to Medical Potential
During his self-experimentation, Davy made a significant observation that hinted at the gas’s future medical application. He discovered that inhaling nitrous oxide provided relief from a severe toothache he was experiencing. This led him to speculate in his 1800 publication that the gas, due to its ability to diminish physical pain, could be used during surgical operations that did not involve extensive bleeding.
Despite Davy’s published suggestion, the medical community did not immediately pursue the idea, and the gas remained a novelty item for public amusement. The shift in perception began when traveling showmen, like Gardner Quincy Colton, toured the United States with their nitrous oxide exhibitions. These demonstrations, where volunteers inhaled the gas and engaged in comical behavior, inadvertently provided critical evidence of its analgesic properties.
An audience member at one of these shows might injure themselves while under the influence of the gas, only to report later that they felt no pain during the incident. This repeated observation of painlessness following minor trauma finally sparked the imagination of medical professionals seeking an effective way to relieve patient suffering during surgery and dental work.
The Official Debut in Dental Surgery
The pivotal moment that transitioned nitrous oxide from a public spectacle to a legitimate medical tool occurred in Hartford, Connecticut, in late 1844. On December 10, dentist Horace Wells attended a public exhibition hosted by Gardner Quincy Colton. Wells watched as a volunteer, Samuel Cooley, inhaled the gas and then badly bruised his leg. After the gas wore off, Cooley claimed he had no memory of feeling any pain from the injury.
Wells immediately recognized the implication of this observation: the gas could be used to prevent pain during dental procedures. The very next day, December 11, 1844, Wells arranged for Colton to administer the gas to him, and his colleague, Dr. John Mankey Riggs, extracted one of Wells’s own wisdom teeth. Wells famously reported that he felt “not so much as the prick of a pin,” confirming the gas’s pain-blocking capabilities.
This self-experiment is widely recognized as the first documented use of nitrous oxide anesthesia for a surgical procedure. Wells began using the gas successfully in his own dental practice, but his attempt to demonstrate the discovery publicly in Boston in early 1845 failed. The patient cried out during a tooth extraction, likely due to an inadequate dose, causing the medical audience to dismiss Wells’s discovery as a hoax.
Establishing Nitrous Oxide in Clinical Practice
Despite the initial public setback in Boston, Wells returned home and continued to use nitrous oxide on his patients. The promising nature of anesthesia was quickly taken up by others, who soon demonstrated the effectiveness of different agents, such as ether and chloroform. These alternative anesthetic gases gained rapid acceptance in both dental and general surgery following successful public demonstrations.
It was not until the 1860s that nitrous oxide was fully embraced by the wider dental community, largely due to the efforts of Gardner Quincy Colton. Colton began partnering with dentists, establishing the Colton Dental Association, which administered the gas to thousands of patients for tooth extractions. This large-scale, successful use provided the necessary evidence to overcome earlier skepticism and solidify its place. The use of nitrous oxide fundamentally changed the dental experience, transforming painful extractions into manageable procedures.