This presentation will provide an update and review of the essentials of nitrous oxide/oxygen sedation. Subjects that will be discussed include a historical review of the agent; a review of the pharmacology, manufacture and safe administration of nitrous oxide/oxygen; an overview of the delivery systems currently available as well as an in-depth discussion of the occupational hazards and adverse effects that have often been associated with its use in dentistry. In addition, nitrous oxide/oxygen use will be discussed in the overall context of the spectrum of anxiety and pain control modalities available in dentistry today.