Nitrous Oxide at the Dentist: Side Effects and Safety

What is nitrous oxide, and how does it work at the dentist?

Nitrous oxide, often called laughing gas, is a gas you breathe through a small mask over your nose. The American Dental Association (ADA) says it is mixed with oxygen and helps you relax. It is one option your dentist may offer to help make you more comfortable during certain procedures.

You stay awake. The ADA says it is not intended to put you to sleep, and you can hear and respond to your dentist. Your dentist asks you to breathe normally through your nose. Within a few short minutes you should start to feel the effects. Learn more about nitrous oxide in our glossary.

Town Center Dental describes its own use of nitrous oxide on its sedation dentistry page.

What happens during the visit, step by step?

Based on the ADA description, a visit with nitrous oxide goes like this:

1. A small mask is placed over your nose.
2. You breathe normally through your nose.
3. Within a few short minutes, you start to feel the effects.
4. You stay awake and can answer your dentist.
5. When the dental work is done, the mask is removed.
6. The effects wear off soon after.

ADA guidance for offices adds that patients should be encouraged to breathe through the nose and limit talking while the gas is in use. Ask your dentist if you have questions about what the visit will feel like.

What does it feel like?

The ADA says you may feel light-headed or have a tingling in your arms and legs. Some people say their arms and legs feel heavy. Ultimately, you should feel calm and comfortable. The ADA also says the effects wear off soon after the mask is removed.

Ask your dentist whether numbing medicine, called a local anesthetic, will also be used for your visit. Your dentist explains which steps the work needs.

What are the side effects?

Most reports describe short effects that fade after the gas stops. The table lists what the sources say.

The review covers procedural sedation in general, not only dental visits, so treat its figures as a rough guide, not a number for any one office.

What does the evidence say about safety?

The review looks at both the benefits of nitrous oxide and the adverse events linked to it. It says the rare vitamin B12 problem should not be underestimated. If screening is possible before use, it says a suitable alternative sedative would be preferable for people at risk.

That is why the health history you give matters. Tell your dentist about:

• Any known vitamin B12 problem or related condition
• Pregnancy, or the chance of pregnancy
• Past reactions to gas or sedation
• Nausea or a recent meal, if the office asks
• Every medicine you take

The ADA says to talk to your dentist about whether nitrous oxide would be a good option for you. A sedative is a medical decision, so let your dentist make it with you.

Why is oxygen given at the end?

The review says there is a risk of diffusion hypoxia after nitrous oxide stops. It says the risk may be minimized when 100% oxygen is supplied after the gas is stopped. ADA guidance for offices also lists delivering 100% oxygen for five minutes after the procedure is over and before removing the mask. This is routine in many offices. Ask your dentist what steps the office follows.

What about pregnancy?

Pregnancy needs a special conversation. The ADA says that while nitrous oxide can be beneficial, pregnant women should avoid exposure because of the possibility that it can harm the developing fetus. That page is written for dental staff and patients. Tell the office if you are, or may be, pregnant, and talk with your obstetrician too. Read our post on dental work during pregnancy for more.

Why do dentists use it?

The review calls nitrous oxide an odorless and colorless gas that is very appealing as a sedative. It lists calming, pain-relieving, and memory-dulling effects, quick onset and recovery, and, in particular, application without a needle. In plain words, it can help ease dental anxiety, starts working fast, and fades fast.

Whether it fits you depends on your health and the work planned. If dental fear keeps you from care, start with the office’s page on dental anxiety management. Our guides on sedation dentistry and dental anxiety explain the choices in plain words.

What should I ask before my visit?

A few questions can make the visit easier:

• Will I need numbing medicine too?
• How will I feel right after the mask comes off?
• Should I eat before the visit?
• Is there anything in my health history that changes the plan?
• What should I watch for afterward?

Write down the answers and keep them with your appointment details.

Next step

To ask whether nitrous oxide may fit your visit, read the office’s sedation dentistry page. Then call Town Center Dental at (636) 273-5866 or request an appointment. Your dentist will talk with you about what to expect.