The most commonly employed technique used in conscious sedation dentistry is inhalation sedation with nitrous oxide and oxygen (N₂O₂ and O₂) or “laughing gas”. It is estimated that approximately 35% of U.S. dentists use nitrous oxide gas to relieve pain and dental anxiety.

The goal sought when laughing gas is used is to eliminate dental anxiety, making the patient more comfortable while the sedation dentist is able to more effectively complete the planned dental care procedure while the patient is sedated.

Some patients at their first laughing gas visit will feel that they are not getting enough “air.” The patient should tell the sedation dentist and he or she will provide them with even more oxygen to breathe. Once the patient is comfortable breathing oxygen, the dentist gradually will introduce nitrous oxide. Over the next three to five minutes, the patient will be asked, “What are you feeling?” as the amount of nitrous oxide is slowly increased.

The signs and symptoms that most patients experience when receiving laughing gas include an initial feeling of lightheadedness, which gradually leads to an all-over feeling of warmth. Many persons mention a comfortable “vibrating” or “humming” sensation. It is common to feel one’s fingertips and hands become “numb.” This same sensation may develop in the mouth. Some patients will mention that their arms and legs feel “very light.” Interestingly, other patients will say that their arms and legs feel “so heavy I can’t even move them.” If either of these occurs to the patient, it is perfectly normal. The individual might notice that they are perspiring a little, too. This is a normal effect of nitrous oxide and oxygen dentistry.

The dentist will talk with the patient throughout the dental care procedure and the individual will be able to respond without any problem. This is a major advantage, and a safety feature, of conscious sedation using laughing gas. If, at any time during the procedure, the patient feels that they are getting too much nitrous oxide or if they begin to feel uncomfortable, they should tell the dentist immediately and within seconds the dentist can adjust the flow of gases, and the patient will feel more comfortable again. Another advantage is that the use of nitrous oxide during a procedure will not affect the patient’s ability to safely drive home after the appointment.

Laughing gas inhalation sedation is highly effective in the management of mild to moderate levels of dental anxiety. It also is an excellent technique in persons who are extreme gaggers; laughing gas usually eliminates or minimizes gagging in most patients. Finally, laughing gas is highly recommended for apprehensive patients who have medical problems such as angina pectoris, persons who have had a heart attack, or persons with high blood pressure, asthma or epilepsy.