There are many types of dental sedation methods.
Nitrous Oxide or Inhalation Sedation
Nitrous oxide sedation has been popular throughout the history of dentistry. 33% of dentists in the United States use inhalation sedation to relax the patient during a procedure. The patient inhales a mixture of oxygen and nitrous oxide through a mask. The gas mixture causes an analgesic and euphoric effect, which numbs and relaxes the patient.
Inhalation sedation has very few side effects.