Last updated 07.15.2026
Can I use nitrous oxide instead of a numbing shot for a dental filling?
Learn when nitrous oxide may be enough for a filling, when you'll also need a numbing shot and what to expect during your appointment.
For small, shallow fillings, nitrous oxide alone is sometimes enough. But for deeper cavities, you'll likely need both. The reason comes down to a simple distinction: Nitrous works on your brain, while a numbing shot works on the tooth's nerve. They do different jobs. Understanding that difference is what makes this decision straightforward.
What you'll learn in this article:
Nitrous oxide calms anxiety and raises your discomfort threshold — but it doesn't numb the tooth, so it works differently than a numbing shot
Cavity depth decides it: shallow fillings may need only nitrous, while deeper ones typically need both for full comfort
If needle anxiety is the real concern, nitrous can make the numbing shot itself far easier to handle
Not sure which option is right for your filling? Set up an appointment with your dental provider — they can review your X-rays and tell you exactly what to expect before you sit down in the chair.
How nitrous oxide and a numbing shot work differently
These two options aren't interchangeable; they act on entirely different parts of your body. That's why one doesn't simply replace the other in most cases.
What nitrous oxide (laughing gas) actually does
Nitrous oxide — often called laughing gas — is inhaled through a small mask placed over your nose. It works on your brain, not your tooth. It calms your nervous system, reduces anxiety and raises your body's threshold for discomfort. You'll feel relaxed, perhaps a little light or tingly, and noticeably less bothered by what's happening around you.
It does not, however, block nerve signals. The nerve inside your tooth is still active. For shallow cavities, that may not matter much. For deeper ones, it does.
What a numbing shot does
A numbing injection delivers local anesthesia directly to the nerve that supplies your tooth. It works by chemically interrupting that nerve signal at the source — so the tooth itself feels nothing: no pressure, no warmth, no drilling sensation. The area becomes completely numb within a few minutes and stays that way for 1–5 hours after your appointment.1 This is what makes deep fillings truly comfortable, regardless of how relaxed you feel otherwise.
When nitrous oxide alone might be enough
Whether you need a numbing shot depends on the size and depth of the cavity. Small cavities that stay in the outer layer of the tooth usually require very little drilling and are less likely to reach the nerve. In these cases, some providers can complete the filling using nitrous oxide alone without a numbing shot. Other comfort options may also be available, depending on the procedure and your needs. If you're hoping to avoid a numbing shot, ask your dental provider what options are appropriate for your specific situation.
If your cavity is small, your dental provider can review your X-rays and tell you whether nitrous oxide alone—or another approach—is likely to keep you comfortable.
When you'll likely need a numbing shot
For deeper cavities — ones that require more drilling and sit closer to the nerve — a numbing shot is usually the best way to prevent discomfort. It blocks the nerve signal directly so the tooth itself stays comfortable during treatment.
If you're also using nitrous oxide, the two work well together. Nitrous helps you stay calm throughout the appointment, while the local anesthesia keeps the tooth numb.
Many patients find that nitrous also makes the numbing shot much easier to handle. Because you're more relaxed, the injection often feels much less stressful than expected.
If you feel uncomfortable at any point during your filling, let your provider know right away. They can adjust the nitrous level, give you local anesthesia or recommend another approach to help keep you comfortable.
Can nitrous oxide help if I'm afraid of needles?
If you're hoping to skip the shot because you're afraid of needles, tell your dental provider before your appointment.
Most providers apply a numbing gel to your gums before giving the injection. If you're also using nitrous oxide, you'll already be more relaxed, which can make the shot much easier to tolerate.
Letting your provider know you're anxious also helps. They can explain each step, go at your pace and check in with you throughout the procedure. For many patients, that makes the experience much less stressful.
Who should not use nitrous oxide?
Nitrous oxide is safe for most patients, but it's not the right choice for everyone. Your dental provider may not recommend it if you are pregnant (particularly in the first trimester), have a breathing condition like COPD, significant nasal congestion on the day of your appointment or a vitamin B12 deficiency.2 Let your provider know your full health history before your appointment so they can confirm whether nitrous oxide is a good fit for you.
What to expect from nitrous oxide at your appointment
Using nitrous oxide is simple. Your dental provider will place a small mask over your nose, and you'll breathe normally. Within a few minutes, most people feel calm, relaxed, and slightly tingly while staying awake and able to talk.
When your procedure is finished, you'll breathe pure oxygen for a few minutes to clear the nitrous oxide. Most people feel back to normal within about five minutes. Unlike oral or IV sedation, nitrous oxide usually doesn't require someone to drive you home, so most patients can drive themselves.
One thing to keep in mind: nitrous oxide is often not covered by dental insurance for adults and may have an additional fee. Your dental office can tell you the cost before your appointment.
Talk to your dental provider about your options
Every filling is different. Whether nitrous alone is enough — or whether a numbing shot is also needed — comes down to where the cavity is and how deep it goes. There's no universal answer, but there is a right answer for your specific tooth.
If you're weighing your comfort options or feeling anxious about an upcoming filling, schedule an appointment with your nearest Aspen Dental provider. They can review your X-rays and explain exactly what to expect — before you ever sit down in the chair.
Can I use nitrous oxide instead of a numbing shot for a dental filling FAQs
How does nitrous oxide compare to oral sedation?
Nitrous oxide and oral sedation are both used to help you relax, but they work differently. Nitrous oxide is breathed through a small nose mask, starts working within minutes and wears off in about five minutes, so most people can drive themselves home. Oral sedation involves taking a prescribed pill before your appointment.
It produces a deeper level of relaxation and requires someone to drive you home afterward. Nitrous oxide is the lighter, faster-recovery option, while oral sedation is often recommended for people with more severe dental anxiety or longer procedures. Your dental provider can help you decide which option is right for you.
Can I eat before a nitrous oxide appointment?
You can, but a light meal is better than a heavy one. Eating a large amount right before the appointment can increase the chance of nausea during or after the procedure. Your provider may give you specific guidance when you schedule.
Will I feel pressure or vibration even with nitrous?
Possibly. Pressure and vibration are mechanical sensations — they don't travel through the same nerve pathway that local anesthesia blocks. Many patients notice some pressure even with a numbing shot. With nitrous alone, some patients notice a little more. If that would bother you, using both together is the more comfortable choice.
Can I ask for nitrous if I'm not particularly anxious?
Yes. Nitrous oxide is available to patients who simply prefer a more relaxed experience. not just those with significant dental anxiety. It's a reasonable comfort option regardless of your anxiety level.
Can nitrous oxide be used for procedures other than fillings?
Yes. Nitrous oxide is commonly used for a range of dental procedures beyond fillings, including tooth extractions, crown placements and other treatments where patients want a more relaxed experience. If you're scheduled for any procedure and want to discuss comfort options, let your Aspen Dental provider know when you book. They can walk you through what's available for your specific treatment.
Sources
1American Dental Association. Anesthesia and Sedation. https://www.ada.org/resources/ada-library/oral-health-topics/anesthesia-and-sedation
2Cleveland Clinic. Nitrous Oxide (Laughing Gas): Uses, Side Effects & Safety. Updated November 20, 2023. https://my.clevelandclinic.org/health/treatments/nitrous-oxide-laughing-gas