Which gas is dental assistants NOT permitted to administer?

Dental assistants are primarily trained to support dental procedures under the supervision of a licensed dentist, and their scope of practice is governed by state laws and regulations. In the context of this question, nitrous oxide, commonly known as laughing gas, is typically classified as a sedative agent that requires specific training and certification to administer safely.

The administration of nitrous oxide involves not only understanding the drug's effects but also monitoring the patient's vital signs and ensuring their safety throughout the procedure. Because of its implications for patient care and the potential for adverse reactions, the administration of nitrous oxide is generally reserved for licensed dental professionals who have completed the requisite training and certification.

In contrast, gases such as oxygen, carbon dioxide, and helium may be used in various dental contexts and do not carry the same level of regulatory restriction. For example, oxygen may be used to support patients in resuscitation or in cases of respiratory distress, carbon dioxide has limited applications, and helium is sometimes used in dental labs for specific purposes. Therefore, nitrous oxide is the gas dental assistants are not permitted to administer.