Nitrous oxide, or “laughing gas,” is used as a mild sedative. It is delivered through a nose hood, and is administered throughout the entire procedure. Nitrous oxide elevates the general mood and can evoke a general sense of well-being. Most importantly, it relieves anxiety and reduces pain during the procedure. In addition, some tingling and numbness may be felt. There are few side effects associated with nitrous oxide, and it has been safely used in dentistry for many years. Nitrous is rarely used if you have respiratory disease and is contraindicated if you are pregnant.