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Numb the Pain - A Look into Local Anaesthetic in Dentistry

Updated: Apr 3, 2023

The following blog on local anaesthetic is bought to you by Dentista Dental Centre- Your Dentist Morley and Dentist Noranda.

Thank goodness that you live in modern times! For hundreds of years, patients and 'surgeons' alike had been grappling of the problem of patients being in severe pain during any procedure. Whilst the first use of general anaesthetic was back in 1846, surgeons or in our case, dentists did not want to have to put a patient under a general anaesthetic just to pull out a tooth. It turns out that our first use of local anaesthetic came to us in 1884, via an Austrian named Koller, who used cocaine of all things to treat an eye of a patient, as it had been discovered that the drug contained local anaesthetic properties. Obviously there were some unintended and unwanted side effects with the use of cocaine, but none the less we had a start. Between 1891 and 1930, other amino esters were synthesized such as propocaine, eucaine, holocaine, orthoform, benzocain and others. From here the journey of local anaesthetic and improvements have been steady and forthcoming.

This article will go into some of the now modern substances you will find in the dental clinic and some of the side effects and implications of the drugs such as how long does local anaesthetic last? and can you drive after local anaesthetic? Simply, local anaesthetic is a miracle of modern medicine and has now improved dentistry to a level where you the patient can get comfortable and pain free treatment. It's hoped that this article may give you confidence and reduce the stress and anxiety that is often associated with dental procedures.

Dr Carla Graneri - dentist performs a dental filling
Dr Calra performs a filling on a patient. The patient is first numbed up with injectable local anaesthetic

What Does Local Anaesthetic Do?

For the most part, the goal of local anaesthetic is to alleviate pain, but other senses may also be impacted, such as the sense of touch, temperature, and other sensations. Local anaesthetic lessens the discomfort and suffering that patients experience during surgical and dental treatments. It is safe and hence preferable than general anaesthesia in many cases, like as caesarean sections.

Any portion of the body, including a finger, eyelid, or foot, may be numbed by applying local anaesthetic near to the nerve, without affecting other parts of the body. Local anaesthetic may be sprayed, gelled, or injected into the mouth, nose, or any other mucous membrane-lined location; surgeries can then be conducted while the patient is still aware.

Dentistry's pain-relieving arsenal would be incomplete without the use of local anaesthetic. Patients, dentists, and dental hygienists have all profited from the development of pain-free dentistry, which has allowed the dentist to achieve significant therapeutic advancements that otherwise would not have been feasible. Amide local anaesthetics, which were first used in dentistry inside the late 1940s, are by far the most often prescribed medications.

Local anaesthetic lidocaine is the most usually used in dentistry (also called xylocaine or lignocaine). Lidocaine is most typically used to numb the region surrounding a tooth during dental operations. There is a lot more Lidocaine needed for root canal therapy than a simple filling.

How long does local anaesthetic last?

When a dentist has to operate on a specific part of the mouth, a local anaesthetic is administered. It will only take some time for you to lose feeling in the region where a local anaesthetic injection or application has been made. When you go to the dentist, he or she will ensure that the region is totally anemic. So how long does local anaesthetic last? While your tooth may be numb for up to three hours, your lip and tongue may remain numb for up to five hours after an injection of local anaesthesia. It will take time for the numb sensation to go away when the anaesthetic is metabolised or broken down in the bloodstream. It's critical that you don't injure the numb region during this period. Resting and taking it easy after any anaesthesia-assisted operation is a good idea since it helps the anaesthetic effects disappear more rapidly.

What types of local anaesthetics

Local anaesthetic may be divided into two primary categories based on how they are delivered.

Topical anaesthetics

Using a topical anaesthetic to numb a specific area of the body is known as a "local anaesthetic." To numb the whole body, even including parts such as the eyeball, nose, and throat. Aerosols, spray, lotions, and gels are all forms of topical anaesthesia.

A combination of different local anaesthetic may be used in certain circumstances to provide a longer-lasting anaesthetic effect.

Topical anaesthetic may be used for a variety of treatments, including the following:

· stitching or removing stitches

· something that requires a needle to be inserted

· implantation of a catheter

· The use of laser therapy

· Refractive keratoplasty

· endoscopy

Benzocaine (Orajel), an topical local anaesthetic, and may help relieve pain from:

· Sores on the gums, teeth, or mouth

· wounds that are still open

· a bad cough

· mild burns;

· Psoriasis itching

· insect stings

· haemorrhoids

Local Anaesthetic Injection

As an alternative to topical use, local anaesthetic may be administered intravenously. As a rule, injectable anaesthetics are utilised for numbing during operations rather than for pain relief.

Procedures that may need a local anaesthetic injection include, but are not limited to:

· Root canals and other dental procedures

· a biopsy of the skin

· the surgical excision of an intruding tumour

· Removal of a mole or a deep wart

· Pacemakers can be implanted

· procedures like a lumbar puncture or bones marrow biopsies for diagnosis

The two most regularly utilised numbing injections in dentistry for local anaesthetic are:

block injection

A section of your mouth, such as one part of your upper jaw, is covered with a block injection.

Supraperiosteal Injections (Local Infiltration)

When a dental operation is to be performed in a specific location of the maxilla or mandible, a supraperiosteal injection (also known as local infiltration) is the best option. An anaesthetic is injected into the nerves that supply the area. This procedure may be used for pulpal anaesthesia of all of the maxillary teeth (both permanent and primary) and the primary molars of the mandible if just one or two teeth need to be treated. In addition to providing regional anaesthetic, it also delivers soft tissue anaesthesia. For youngsters, the permanent first molars, the injection site must be free from disease or acute inflammation as well as locations where thick bone covers the tip of the tooth. Several needle insertions and the use of greater quantities of local anaesthetic may lead to toxicity, hence it is not suggested for big regions.

During a treatment that needs dental local anaesthetic, your dentist will dry a portion of your mouth with cotton or air. In certain cases, your dentist may numb the region where he or she intends to inject the anaesthetic using a gel. A fear of injections may be alleviated with the use of this method. The anaesthetic will then be injected into the region by your dentist. You won't feel a thing when the needle is inserted. Only the sting of the drug travelling into your tissues is felt by the majority of patients.

Side Effects of Dental Local Anaesthetics

In dentistry, anaesthetics are the most often utilised medicines, and patients seldom have unpleasant responses to them. This is not a long-term issue, but rather a small and transitory one.

· Anesthetics may have the following unusual negative effects:

· If the injection strikes a blood artery, it might result in a hematoma.

· Due to the vasoconstrictor, the heart rate rises.

· The sensation of numbness outside of the targeted location. For a few hours, this may alter the appearance of your face. Blinking and other facial motions might be hindered as a result.

· Damage to a nerve as a result of the injection. This may cause numbness and agony that lasts for months until the nerve recovers.

Driving and Local Anaesthetic

Your ability to drive following local anaesthetic recovery will be determined on the specific surgery you had. How well that you can drive will also depends about whether or not you have had anaesthetics.

Probably wait 24 hours before driving after receiving a sedative and local anaesthetic. Consult your physician for guidance. You are legally responsible for maintaining control of the vehicle at any and all times. To avoid any complications, it is advisable to wait till after your treatment or anaesthesia.

Local Anaesthetics Nose Job

Local anaesthesia is an option for rhinoplasty surgery! When the patient's nose needs just little contouring, such as "tip work," local anaesthetic is chosen over general anaesthesia. A brief inhibition of impulses from your nerves leads in total sensory depression in the operative area, which is achieved by administering local anaesthetic. Cognitive and motor capabilities are unaffected in the patient, who is able to breathe on their own without assistance. The patient is completely pain-free while receiving local anaesthetic, allowing them to have a full discussion.

Local Anaesthetic Overdose

Inadvertent intravascular injections or repeated injections of local anaesthetics might result in an overdose of the anaesthetic. Overdosing on local anaesthetics stimulates the brain and, to a lesser degree, the heart, before causing depression.

After dizziness, anxiety, and confusion, further symptoms of the brain include diplopia, tinnitus, sleepiness, and circumoral tingling. Symptoms such as twitching, tremoring, slurred speech, and shivering precede the emergence of more overt seizure activity. Respiratory arrest and unconsciousness may occur.


Gone are the days where you as the patient has to go through pain and suffering when going to the dentist. Local anaesthetic, have we can seen, will numb the area temporarily, while the patient is being worked on all whilst being perfectly safe and effective for the patient. If you are looking for a Dentist in Morley or Dentist in Noranda, please call or book online today with Dentista Dental Centre. We look after your smile one tooth at a time.

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