Updated: Oct 14
To numb your mouth, your dentist will use a combination of topical and local anesthetics. The both of them come in different forms and consequently are also administered differently as well.
In addition to the topical and local anesthesia, your dentist may employ other techniques and methods to keep you comfortable during the procedure. There is oral sedation, nitrous oxide, IV sedation, and general anesthesia. They're all used in different settings but they still require at a minimum local anesthesia for your mouth to be numb.
Table of Contents:
Topical anesthesia to numb your mouth
Topical anesthetics, which are commonly referred to as the pre-numbing gel, can be used to numb your mouth. They are often used prior to local anesthesia in order to make the injection more comfortable. The great part of it is that they're also available over the counter and may be purchased at your local pharmacy.
Most dentists will use the topical anesthetic prior to giving you the dental numbing shot. The reason is because it prepares the injection site by numbing it so that the penetration hurts less.
How to use the topical anesthetic:
Dry the application site.
Scoop some of the topical anesthetic with a cotton tip.
Apply numbing gel to area of choice.
Rub it in with circular motions a couple of times.
Wait 2-3 minutes for the effects to begin.
Remove cotton tip with anesthetic.
The product that your dentist uses is by prescription only and this is what it looks like:
It comes in a little plastic jar and is in a gel-like form. The gel may come in a variety of flavors such as mint, bubblegum, pina colada, raspberry, strawberry, grape, and etc.
What it is made out of is primarily 20% benzocaine. That is the numbing agent.
Available as over the counter
You may not be able to purchase the exact one as your dentist but there are similar topical anesthetics available over the counter. The two most popular are called Orajel and Anbesol.
Most people often purchase them and use them for toothaches. Although how effective they are at relieving tooth pain is up for debate because research shows that orajel only lasts about 20 minutes.
Despite not being very effective for numbing the tooth, it is mildly more effective in numbing soft tissue like your gums. That is actually what your dentist also uses it for, to numb the soft tissue in your mouth. It is basically used to prepare the soft tissue for the injection site. Your dentist does not use it to numb your tooth.
Last but not least, don't forget that pregnant women should try their best to avoid topical anesthetic. That means you shouldn't be using orajel or anbesol if you're having a toothache and you're pregnant. The best thing to do would be to see your dentist as soon as possible.
Local anesthesia for numbing your mouth
The topical anesthetic is good for numbing the soft tissue but it is the local anesthesia that truly numbs the teeth. Without the local anesthetic, you would feel everything that your dentist is doing during the procedure. Therefore it is quintessential that you receive some local anesthesia prior to starting any dental treatment.
How to use local anesthesia:
Dry the injection site.
Apply topical anesthetic to site.
Wait 2-3 minutes.
Load the local anesthetic syringe.
Attach needle to syringe.
Wait 3-5 minutes for effects to begin.
Begin dental treatment.
This is a photo of the local anesthetic armamentarium:
This is what it looks like when you load the syringe with the anesthetic carpule:
Then depending on what your dentist needs, they may opt to use the long needle or a short needle. After that, your dentist needs to attach the needle to the syringe and it is ready for injection. That is basically what your dentist uses to numb your tooth and your entire mouth!
Type of local anesthesia
Despite most patients calling the local anesthetic novocaine, we actually no longer use that. Here are the four most common anesthetics that dentist use in modern day:
They all wear off at different rates but on average it takes about 2-3 hours after the procedure. The only exception would be Bupivacaine, which can last up to 4-8 hours.
In addition to the topical and local anesthetic, your dentist may employ other techniques to make the dental procedure more comfortable. These methods do not numb the mouth per say but they certainly do make it more tolerable.
Oral sedation. This is when your dentist gives you an anxiolytic, which comes in a pill form. The most common one is called Valium. For this to work, you must take it an hour prior to your appointment and you will also need a chaperone to take you home.
Nitrous oxide. This is most commonly known as laughing gas. In our experience, once we turn on the nitrous oxide, most patients won't even feel the local anesthetic injection or perhaps the right word is, they no longer mind it. For this technique, you do not need a chaperone because most people are fully conscious within half an hour after the procedure. There is usually a resting area for patients to recover prior to trekking back home.Here are pictures of both the long and short, attached to a fully loaded syringe:
IV sedation. This technique utilizes administering medication via IV to put you to sleep for your dental procedure. It is most commonly used at oral surgery offices during extraction of impacted wisdom teeth. Most people do not want to be awake for the removal of the impacted molars. You certainly do need a chaperone for this technique and there are also eating/drinking limitations the night prior.
General anesthesia. In order to receive general anesthesia, you must go to a hospital because there is no dental clinic or outpatient clinic that will be able to administer this. This type of anesthesia is reserved for full mouth rehabilitation cases or broken jaws. It is also not uncommon for pediatric patients who require a lot of treatment to undergo this as well.
Just to be clear, all of these techniques will numb your consciousness but won't necessarily numb your mouth. Even after being sedated or undergoing general anesthesia, your dentist still needs to administer the local anesthetic in order for your teeth to be numb. After you're fully numb, you won't feel a thing when you get your dental filling.
Your dentist uses a combination of topical and local anesthetic in order to numb your mouth. The topical is applied via a cotton tip applicator while the local anesthetic is administered via a syringe. The both of these together will make your mouth numb enough to tolerate any dental procedure.
Author: Written by Dr David Chen, a long island city dentist.