Local anaesthetic

Dental local anesthesia is used for everything from simple dental fillings to crowns and root canals. When you schedule a dental procedure with us, there's good chance that we’ll have to use an anesthetic.

What is Local Anesthesia?

Dentophobia is a very real issue for people worldwide. Fear of the dentist keeps many potential patients from sitting in our dental chair even if their teeth are causing them excruciating pain. However, some people don’t have an intense phobia and are just afraid that their procedure will cause them pain.

Local anesthesia is how we, as dental professionals, help you feel comfortable in the dental chair and reduce dental anxiety.

A quick injection into the gums near the tooth is often more than enough to sufficiently numb a patient and allow them to have much-needed dental work performed. We'll even apply a topical numbing agent to the area before we inject the anesthesia to reduce the risk of pain as much as possible.

Topical dental gel
Topical Jel

Local anesthesia is a medication used to block pain in a specific area, in this case, your mouth.

People have been using this type of medicine for over 175 years, and you’ll often find many names for anesthesia, such as:

  • Articaine
  • Bupivacaine
  • Lidocaine
  • Mepivacaine
  • Novocain  
  • Prilocaine
Articaine anesthetic

A few of the procedures that may require numbing, include:

You won’t need a local anesthetic if you’re having your teeth cleaned.  

Instead, for one of the other procedures, you’ll come into our office, sit in the chair and an assistant will apply a topical numbing agent. Within just a few minutes, the area where we plan the injection will be numb and we’ll inject the agent.

For most people, they’ll be sufficiently numb in 5 – 10 minutes and ready for the procedure.

Because most dental will last 30 – 60+ minutes, we add epinephrine to increase the effects of the anesthesia.

How Long Does the Anesthesia Last?

Every procedure will require a different amount of anesthesia. For example, a fast cavity filling will require a lower dose of anesthesia than a root canal because of the time difference between the procedures.

You may feel the anesthetic used for a filling wear off in an hour or two after the procedure.

However, in the event that we need to use a higher dose or long-lasting solution, you may have numbness for 2 – 5 hours after the procedure. In most cases, people will notice:

  • Extreme numbing feeling for the first hour or two
  • Lower level of numbing thereafter

When you’re still feeling very numb, it’s not advised that you eat. The tongue may be numb, and there’s a risk that when you chew, you’ll bite your tongue. There are instances where people have caused significant damage to their tongue because they tried eating while still numb.

Once the numbness wears off, you can begin eating again.

If you have a filling, you can begin eating once the numbness subsides. However, if you’ve had a tooth extraction, you will need to adapt your diet to eat soft foods until the gum is sufficiently healed.

We'll advise you on the dos and don’ts following your procedure so that you know when you can eat and go back to your normal routine.

Note: Local anesthesia allows you to remain alert and awake during your entire procedure. You can also drive yourself home because there are no sedation or consciousness-altering effects.

While the vast majority of our patients will not experience side effects from anesthesia, there are some that we think you should know about before coming into our office.

What are the Potential Side Effects of Local Anesthesia?

Local anesthesia is tolerated well by our patients, but there are potential side effects that everyone should know. The following issues may arise:

  • Headache
  • Dizziness
  • Numbness
  • Sweating
  • Nausea
  • Tiredness

However, if you need to have something like epinephrine added to help with the numbing, it’s possible that your blood pressure and heart rate can rise. This is why we ask our patients if they’re taking any medications or have any specific health issues before a procedure.

If we know that you’re taking medication for heart-related issues, we can take appropriate action to reduce the risks of complications during your procedure.

In VERY rare cases, someone may also have an allergic reaction to the anesthesia. Reactions can vary from very mild to severe, so it’s important to tell us if you have any known allergies. An allergic reaction may be something as simple as swelling of the lips or mouth or something as serious as difficulty breathing.

Knowing about any allergies beforehand can help our team find an anesthetic option that works best for you.

There are also some patients who are at higher risk of complications.

People at Higher Risk

You may be at a higher risk of complications from anesthesia if you have any of the following:

  • Heart problems
  • COPD
  • High blood pressure
  • Sleep apnea
  • Obesity
  • Behavior disorders
  • Seizure disorders

Additionally, if you’ve had gastric bypass surgery or suffer from substance misuse, you also may be at a higher risk of side effects.  

Many of our patients are starting a family or expanding their family. If you’re pregnant or plan to be, the section below should help to ease your mind.

Can You Have Local Anesthesia While Pregnant?

Dental emergencies can strike at any time – including when you are pregnant. Currently, research shows that lidocaine is relatively safe, and there is no clear evidence that it can increase the risk of complications for either the baby or the mother.  

That being said, it’s important to note that local anesthesia can still cross the placenta and enter the fetus. Because it can cross the placenta, there is always some risk that it may affect the baby.  

For elective dental procedures, it may be best to simply wait until after the pregnancy. Your dentist and doctor can discuss the risks with you and determine which course of action is best.  

In emergency situations, your dentist will discuss the best way to handle the procedure. A root canal or extraction, for example, may be necessary and the benefits of the procedure may outweigh the risks.

Anesthesia and Pediatric Dentistry

When children need to have certain dental procedures performed, parents are naturally concerned about the use of local anesthesia. Unfortunately, more than 621 million children worldwide have dental caries. To make the treatment of cavities comfortable for children, dentists use some form of sedation.

While there are several options for sedation dentistry for children, local anesthesia is common. Of course, dentists will take every possible step to make children feel as comfortable as possible with the process. Positive experiences with local anesthesia and other procedures early on will help instill positive associations with going to the dentist – something we all want! For example, a STA wand anesthetic device can dramatically reduce pain because it utilizes a precise control of flow rate and a very small needle.

Singel tooth anesthetic device - STA Wand
STA Wand

Aftercare for Local Anesthesia

Aftercare is important when children receive local anesthesia. Local anesthesia has the same effect on children that it has on adults.  

  • If the procedure was on the lower jaw, your child might have numbing in the lower jaw, lip and surrounding tissue.
  • If the procedure was on the upper jaw, your child may have numbing in the upper jaw, lip and surrounding tissue.

Children may not understand that the local anesthesia is what caused the numbing in their mouths. They may try to scratch, chew or play with the numbed area. It's important to try and discourage this behavior, as it can cause irritation or even swelling and abrasion to the tissue.

Following your child’s appointment, monitor their behavior closely for approximately two hours to check for negative side effects. Consider giving your child a liquid or soft diet until the anesthetic has worn off.

There is a small group of people who cannot have a local anesthetic, and while very rarely does this include a child, there’s always a risk that it can.

Who Can’t Have Local Anesthesia?

For certain groups of people, extra caution must be taken when administering local anesthesia. These include individuals with the following conditions:

Heart Disease

It is a common practice to add adrenaline to local anesthetics, so caution must be taken when working with patients who have cardiovascular disease. Lower doses of adrenaline may be needed in this case.  

Renal or Hepatic Impairment

Patients with renal or hepatic impairment may also need lower doses of anesthetics. Reduced liver or kidney function can affect how the anesthetic is metabolized. Lidocaine, for example, is almost entirely metabolized by your liver.  

Extra care should also be given when administering local anesthesia on elderly patients. Due to reduced liver and kidney function, a lower dose should be considered.  

Overall, local anesthesia is considered a relatively safe way to prepare patients for uncomfortable dental procedures. However, it’s important to know what to expect and the potential side effects that may occur. We will discuss any concerns you may have and explain how the procedure will work to make you feel more comfortable.

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Dr. Gurpreet Sidhu - Dentist at Lighthouse Dental Centre and Blue Water Dental
Dr. Gurpreet Sidhu

With nearly two decades of experience, Dr. Sidhu enjoys helping his patients learn about dentistry. Knowledge is meant to be improved, challenged and shared.

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