Nitrous oxide, or laughing gas, is the most frequently used method for easing mild to moderate anxiety. Administered through a small mask that fits over your nose, it is an effective way to calm anxiety, raise your pain threshold, and even make time seem like it's passing quicker than usual. As the gas begins to work, you will become calm, although you will still be awake and able to talk with the dentist.
At the end of your appointment, you'll resume breathing regular oxygen, and all the effects of nitrous oxide will disappear, so you can resume your normal activities immediately.