Mechanism of Action of Nitrous Oxide

  • Dimitrios Emmanouil


The use of nitrous oxide sedation can reduce anxiety and pain associated with the treatment in a dental office. But how and what does nitrous oxide do? In fact, for more than 120 years, nitrous oxide was being used without a clear understanding of its mechanism of actions. This chapter will take our readers “backstage” where they will develop a better understanding on how nitrous oxide brings about its effects and what makes it useful in dentistry. A detailed description will be given on the way nitrous oxide interacts at a molecular level to bring about its anxiolytic, euphoric, sedative, and anesthetic effects. Bringing all this back to clinical setting, different stages of anesthesia, levels of sedation, and signs which suggest normal sedation vs oversedation shall be discussed.


Mechanism of action of nitrous oxide Levels of sedation Relative analgesia Conscious sedation Signs and symptoms of nitrous oxide in children 

Supplementary material (168.5 mb)
Video 3.1 This video presents the eye response during inhalation sedation. The clip shows reduced blink rate, decreased movement of eye balls, and drooping upper eye lids. After the inhalation sedation procedure ends, eyes appear brighter, with a normal blink rate and movement of eye balls (MOV 185752 kb) (136 mb)
Video 3.2 This video describes what a child feels when inhaling nitrous oxide sedation. The first child says that she feels that her entire body is numb. The second child talks about his imagination while watching a cartoon show on screen while inhaling the gas. Changes in voice are well appreciated in this clip with pitch of voice higher and slight pauses while speaking. The third child has a euphoric effect and later describes the surroundings, indicating that the child is well aware about the surroundings (MOV 139308 kb)


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Authors and Affiliations

  • Dimitrios Emmanouil
    • 1
  1. 1.Department of Pediatric DentistryDental School, National and Kapodistrian University of AthensAthensGreece

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