How long does dental anesthesia last? Types and side effects

Anesthesia is a method of managing pain during medical treatments. It is hard to imagine undergoing any dental treatment above a cleaning without it.

The type of sedation that will be used depends mostly on whether you have dental anxiety. If someone is very nervous about a procedure or has trouble sitting still (especially small children), they might need a more intense form. The complexity of the procedure is also a big factor.

There are five common types of dental anesthesia.

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Local anesthetic

Local anesthesia is the most common method of pain control at the dental office. It is used with most procedures other than routine exams, X-rays, and cleanings.

When it is used

If you’ve ever had a cavity filling you are probably familiar with it already. It is also used when preparing teeth for crowns, treating gum disease, and during root canal treatment.

The bravest of us might do with this type of sedation while their teeth are being extracted.

Dr. Namrita Harchandani
No matter whether you choose any type of sedation, local anesthetic is always used. It is a part of the cost of the procedure.

How it works

It is administered by injection. A topical anesthetic might be used to numb the area before it is pierced with the needle.

The syringe will be filled with a chemical (often this is lidocaine, also known as xylocaine or lignocaine). It works by blocking the nerves that sense pain and carry the information to your brain.

The lidocaine might be supplemented with trace amounts of epinephrine. It helps to improve the intensity and duration of the anesthesia as well as control bleeding.

Duration and intensity

Lidocaine is not very intense, especially at such a small dosage. It will certainly prevent you from feeling pain in that specific area, but you will remain fully awake and aware.

You won’t feel any effect on your body after two hours. It will be perfectly fine for you to drive yourself home after the procedure. If you experience discomfort at this point you will have to take an aspirin or another painkiller.


A local anesthetic will most likely be included in the price of the procedure you are having.

It would be unreasonable to charge for it separately, as it is an inherent part of any painful procedure. It prevents you from moving around due to pain or anxiety, which would make the treatment difficult for the dentist and unsafe for you.

Laughing gas

Laughing gas is the second most common type of anesthesia. It is often portrayed in movies or videos by YouTubers, but its effects are rather exaggerated.

When it is used

Laughing gas often accommodates wisdom tooth removal. It is great with procedures that, apart from causing pain and discomfort, are also a source of anxiety.

That is why it is used with minor procedures on toddlers. Filling cavities, for example, becomes a lot less stressful this way.

How it works

The scientific name for this chemical is nitrous oxide. “Laughing gas” comes from the fact that it makes you feel very calm and relaxed, almost giddy. You might find yourself giggling after the procedure.

You will breathe it in through a small mask that fits over your nose. A tube will feed the gas in. Sometimes the tube is inserted directly into the nose. This type of anesthesia is extremely safe, even for two- or three-year-olds and pregnant women.

Duration and intensity

The effects of laughing gas are very short-lived. You should start to feel normal within minutes of cutting the supply.

You might not be able to remember the procedure properly. You will, however, be able to follow simple instructions. Laughing gas is often used alongside other types of anesthesia, so you can expect to get an injection as well.


Nitrous oxide is an expensive form of anesthesia. It will cost upwards of $50 dollars per visit. Some offices charge per hour, or even per fifteen-minutes increments.

Since it is difficult to predict how long the procedure will last beforehand, you should put aside some extra credit if you are set on this type of sedation. It is unlikely that insurance will cover these costs.

Conscious sedation

Also referred to as procedural sedation, this method is also quite a common one at the dental office.

When it is used

It is habitually used when treating children, but it can also be used with adults. The procedures in question are uncomplicated surgical ones, usually lasting less than an hour. A good example is a wisdom tooth extraction.

How it works

You will be asked to take a drug orally about thirty minutes to an hour before your procedure. The type of medication is usually a benzodiazepine.

This chemical can be used to induce sleep and relaxation. It can cause temporary memory loss and helps to reduce anxiety. Benzodiazepine is also a muscle relaxant, so you might find yourself moving slower than normal as well.

Duration and intensity

This type of anesthesia helps to relax you, not put you to sleep. You will remain awake, but will not remember what was happening exactly. The dentist or dental assistant might give you simple instructions which you will be able to follow.

You will be in this “twilight” state for about an hour. You might feel drowsy and will need someone to take you home. Some patients find they can’t concentrate the next day, so you might have to take a day off work.

You should be able to breathe by yourself, but respiratory and resuscitative equipment will be available at the office to ensure your safety.


This form of anesthesia is quite expensive. You might have to set aside about $170 for mild cases.

Intravenous sedation

This is a lot more invasive than local anesthesia or laughing gas. It is also unsuitable for those with needle phobia.

Dr. Peter March
If you are undergoing sedation you will have to fast for some time before your procedure to avoid nausea.

When it is used

Intravenous mediation is used most often with oral surgery. This means you can ask your dentist about it every time you have a tooth extracted.

It can be used for root canal treatment or fillings if you are very sensitive to pain or very nervous. More often than not, however, for these you will have one of the less invasive kinds of anesthesia.

Most general dentists in the U.S. are not licensed for IV sedation. It is usually performed by specialists like oral surgeons or endodontists.

How it works

It is sometimes called conscious sedation and it is exactly that. You will not be fully asleep, but you won’t remember the procedure either.

Your hand will be strapped down and a needle will be inserted into your vein. The sedative will be delivered slowly throughout the procedure. The dose is easy to control.

It might be used with other kinds of anesthesia, typically an injection. It will be administered after you are sedated.

Duration and intensity

It’s a good idea to abstain from eating and drinking for about eight hours before your procedure. Your dentist will give you more detailed instructions during your preliminary exam.

During the procedure, you will not be entirely “present” but you will be aware if someone, for example, touches your arm.

The drug will still be in effect after the procedure ends. You shouldn’t drive in this state, so it’s a good idea to organize somebody to assist you.


There is always an additional charge. It is usually calculated in fifteen-minute increments. The first quarter of an hour will probably cost around $200 while the additional ones might be slightly cheaper.

As with the laughing gas, it is good to be prepared for an unexpected, higher cost. Predicting the exact length of the procedure beforehand is not always possible.

General anesthesia

This is the most expensive type of anesthesia. It is only recommended in extreme situations.

When it is used

This type of sedation is used with heavy-duty dental work. Oral surgery, with complex wisdom tooth extraction in particular, is a common opportunity to use it.

Other instances when this type of anesthetic can be taken advantage of include implant placement.

How it works

General anesthesia can be administered orally, via the lungs, or by way of a vein. A chemical with properties that interrupt nerve signals will make you doze off.

Someone other than your dentist or oral surgeon will be sedating you. You will probably be fully out within a couple of minutes.

Duration and intensity

You will be completely unaware of your surroundings. It might take up to an hour after the surgery is finished for you to regain consciousness.

Even then you might feel drowsy. You are going to have to be driven home, that is if you haven’t arranged to stay in a hospital overnight.


This is the most expensive kind of anesthesia. It requires an anesthesiologist, which drives up the price greatly. Not many offices have the means to do this. The initial fee might be around $250, while each additional fifteen minutes might be around $200.

Dr. Namrita Harchandani
An anesthesiologist is always required to perform general anesthesia and the dental surgeon performs the procedure. There is a team of medical professionals involved in this procedure and therefore costs may be significant.

As with other types of sedation that are charged this way, it is difficult to predict how long you will have to be under. Complex procedures such as the ones mentioned above often pose unexpected issues which can drag the process out.

Side effects

Even if you aren’t allergic to the drugs used and even if everything is done properly, you still might experience minor side effects. Here are a few you might expect:

  • lightheadedness,
  • euphoria,
  • confusion,
  • dizziness,
  • drowsiness,
  • ringing in your ears,
  • blurred vision,
  • vomiting,
  • slow or fast heart rate,
  • low or high blood pressure, or
  • tingling.

None of these, however, will last very long. If you still feel uneasy the day after you should consult with a doctor.


Which dental procedures require the use of anesthesia?

Most dental procedures other than exams require some sort of pain management. The most common type is a local injection, used during many treatments including fillings, root canals, and extractions.

How painful is dental anesthesia?

Anesthesia itself was designed to stop you from experiencing pain. You might feel discomfort during application, though.

A local injection can cause irritation, similarly to IV or general sedation, which also require tissue to be pierced. You might have slight bruising or tenderness after the procedure. Other types like orally-administered conscious sedation or laughing gas should not cause any inconvenience.

What does dental anesthesia feel like?

Depending on the severity, you might be fully conscious, able to follow instructions, or completely put under.

The lightest forms are topical injections and laughing gas. The latter might make you feel drowsy, but you should be able to drive yourself home.

IV and conscious sedation induce the effect of grogginess enough that you won’t be able to remember the procedure. You will, however, be able to follow simple commands such as “sit up” or “spit”.

General anesthesia knocks you completely unconscious, probably for a few hours after the procedure as well.

How long does it take for dental anesthesia to wear off?

Laughing gas should wear off almost instantly. A local injection will block nerve pathways for a few hours. After that you might have to rely on OTC painkillers. It won’t have any effect on your mental state.

Conscious and IV sedation will take a couple hours to leave your system. General anesthesia lasts the longest and you might have to stay in the hospital overnight.

Is dental anesthesia safe?

Anesthesia does carry a small risk of some side effects such as prolonged drowsiness or nausea. There is no need to worry about serious danger unless you have a condition that prohibits the use of sedation.

In the case of more invasive forms, an anesthesiologist will oversee the procedure and be present the entire time. Before administering the drug, the doctor will conduct a thorough medical review. This allows the team to pick the best medication and makes the procedure safe.