Nitrous Oxide Indications, Side Effects & What To Expect

Author: Dr. Alison Vitelli, DMD

Many of our patients have requested the use of nitrous oxide, or commonly known “laughing gas”. This gas has been around since the 1770s and vastly used in the medical field since then. But it was not until mid 1840s that Horrace Wells, an American dentist in Connecticut, used nitrous oxide as an analgesic for dental procedures.

Today in dentistry, nitrous oxide is mostly used in lower doses with the purpose of relaxing a patient and easing the anxiety related to dental procedures. Some of the signs of effective administration of nitrous oxide are relaxation, feeling of heaviness on extremities and torso, tingling of the fingertips and sounds will appear to be far away. As many may be wondering, yes, it does make some of our patients burst out in laughter.  It does have partial amnesic effects, so you may not remember all that happens in the room while you are under the effects of the gas.  

One of the most significant properties of nitrous oxide is that it does not get stored nor metabolized (or chemically changed by our body). Although the exact path of action of this gas is still not fully understood, it has the ability to act on certain neuroreceptors to allow the feeling of relaxation, happiness and lower anxiety, without changing its chemical form. As I tell my patients, the way you breath it in, is the same way you breath it out. It is administered together with oxygen. Administering the nitrous oxide always starts by providing the patient with an influx of 100% oxygen for 5 minutes. This is followed by gradually introducing the nitrous oxide for up to a maximum of 50% mixture during the procedure. As soon as the dental procedure is completed, the nitrous oxide gets titrated down until 100% oxygen is administered for another 5 minutes. Following these protocols reduce the potential of developing diffusion hypoxia, which is a rapid change in the gas balances inside of the lungs that allow proper physiologic functions.

As with everything in science, there are some side effects, as well as contraindications to the use of nitrous oxide.  Some absolute contraindications are patients who suffer from COPD, since the reduced capacity and function ability of the lungs will not agree with the introduction of elevated gas pressure. Other relative contraindications are nasal congestion and claustrophobia, just to mention a couple of the most common ones. Although rare, one of the most common side effects experienced during usage of nitrous oxide is lightheadedness and vomiting, but can certainly be avoided with proper communication and consistent assessment from the clinician. At Spring Lake Dental Group, we ask our patients who request the use of nitrous oxide to refrain from eating at least 2 hours prior to the dental appointment and for it to be a light and lean meal.  This will help decrease the side effects of nausea and vomiting.

If the use of nitrous oxide is something you think may help you with future dental visits, talk to your dentist or hygienist!