Nitrous Oxide (Laughing Gas): Now, this isn’t really a service in itself, it’s used to make other treatment more comfortable. This is the famous dental anesthetic. It’s safe, has proven effective over a long period of time, and is pleasant. You will be given a mask that allows you to breathe in through your nose and out through your mouth. In about 30 seconds to 4 minutes you will notice a more sedate feeling, and your cheek and gums may go numb. After this any needed local anesthetic is applied and treatment begins. Afterwards, you will be given pure oxygen to breathe for about five minutes to dissipate the effects of the nitrous and return you to a normal state.