Local Anesthesia in Dentistry – Purpose, Usage & Risks

Local Anesthesia in Dentistry

Local anesthesia is a numbing medication that makes a small area of your body insensitive to pain. It comes in handy for minor surgeries and while stitching up wounds. Local Anesthesia in dentistry is common and various dentists use it for many procedures on a daily basis.

Lignocaine or Lidocaine is the most commonly used Local anesthetic agent. Use of local anesthesia is mandatory for dental procedures like root canal therapy and tooth extraction.

Local anesthesia contains a numbing agent and adrenaline with trace amounts of acids and buffering agents. It is available in many forms like gels, creams, sprays, and injectable solution. Gels, creams, and sprays are topical local anesthetics.

Injectable solutions are mandatory for all surgical and invasive non-surgical procedures. There are a few associated risks that come with the use of local anesthetics.

Your dentist may use different anesthetic blocks depending upon your need. These techniques include nerve blocks and regional blocks.

People with high blood pressure, heart conditions, and diabetes should avoid conventional local anesthetics which contain adrenaline. There are readily available substitutes for such cases.

Let’s have a look at the details of usage and contents of local anesthesia.

What is Local Anesthesia?

Local anesthesia is a numbing agent that soothes your tissues during a medical or dental procedure. It has a numbing effect on the peripheral or externally lying nerves of your body.

Local anesthesia penetrates your skin and deeper tissues in a small area. Hence, the name local anesthesia is appropriate as it does not affect your brain or spinal cord.

Your doctor uses this for minor procedures like an explorative examination, biopsy or stitches. Also, they are more widely in use at your dentist’s clinic. Some dental procedures can be mildly painful, and some cause a lot of discomforts.

To avoid your apprehension, your dentist might use a local anesthetic in even minor procedures like scaling and root cleaning. (1)

Some commonly used local anesthetics are –

  • Lignocaine / Lidocaine
  • Bupivacaine
  • Procaine
  • Benzocaine

Lignocaine is the most frequently used local anesthetic in both medical and dental practice. Lignocaine has the least side effects and maximum potency.

Contents of a local anesthetic solution

Local anesthetic contains the following-

  • Numbing agent in significant concentration (preferably Lignocaine)
  • Sodium hydroxide
  • Sodium chloride
  • Dilute form of Adrenaline or Epinephrine (in a ratio of 1:2,00,000 units)
  • Trace amounts of Hydrochloric acid
  • Buffering solutions
  • Preservatives

Different types of Local Anesthesia

You can receive a local anesthetic in the following forms-

  • Numbing gels
  • Anesthetic creams
  • Injectable solutions

Uses of Local Anesthesia

Local anesthesia is mandatory for the following minor medical procedures-

  • Excision or removal of boils and blisters.
  • Placing stitches on large wounds.
  • Cleaning large wounds.
  • For removal of warts and skin tags.
  • Numbing gels are necessary for extensive muscular pain.
  • Sample collection for tissue biopsy.

Types of anesthetic techniques used by dentists

The following are the various types of anesthetic techniques that your dentist might use depending upon the requirement –

  • Infiltrations – for single tooth treatment.
  • Nerve block – for extraction and root canal of more than two teeth.
  • Regional block – for treatment of an entire segment of your jaw.

Purpose of Local Anesthesia in dentistry – Dental Anesthesia

Local anesthesia is necessary for minor medical procedures. But, local anesthesia is a significant aspect of almost all dental procedures which include –

Root canal therapy

Root canal treatment involves pulp. Pulp in your tooth has all the nerve endings in it and is very painful to touch. Hence, using an anesthetic before this procedure is essential.

Tooth extraction

We all know how painful tooth extractions can get. A regional nerve block, numbing an entire jaw section of the affected side is necessary. The numbing action of the anesthetic helps with post-extraction pain as well. (2)


Debridement or deep gum cleaning can be painful and causes a lot of bleeding. Anesthetics ease not only the discomfort but also adrenaline clears the field for operation. Adrenaline reduces excessive bleeding.

Orthodontic procedures

Sometimes the application of wires and braces can get painful. In such cases, a small nerve block may be helpful during the process.


Removal of gingiva is a major surgical process. Hence, it is unwarranted to emphasize the need for using anesthetics. It also helps in post-operative pain.

Splinting of teeth

Loose teeth are brought together with wires in this procedure. Splinting might make you uncomfortable due to swollen gums. Anesthetics ease the pain and discomfort during splinting procedures.

Deep cavity filling

Deep cavity filling is a tricky procedure where your dentist works close to your dental pulp. An extra anesthetic cover is always a good idea during this procedure.

What to expect after administration of anesthesia?

Different people have different experiences with local anesthesia. But, the most common signs that you may experience after the administration of local anesthesia in your mouth are-

  • There is a heaviness in the area of injection.
  • Numbness might occur in a specific side of the jaw.
  • Part of your tongue and lower lip gets numb in cases of lower jaw local anesthetic procedures.
  • Minor swelling might appear in the area.
  • Excessive salivation might occur.
  • Little bleeding may occur around the area.

These symptoms subside in a few minutes after which you don’t feel anything at all for the next few hours.

How long does the anesthetic effect stay?

Lignocaine is a long-acting local anesthetic agent. Its effect may last ranging from 2 to 6 hours depending upon the amount of solution infused.

An anesthetic solution with high amounts of adrenaline acts longer. Adrenaline acts as a vasoconstrictor. It constricts or narrows your blood vessels so that the anesthetic stays longer. (3)

Risks and side effects of Local Anesthesia

Local anesthesia is a necessary evil. Hence, it comes with its string of risks and side effects. Let’s review the associated risks –

In diabetic patients

Studies show that if you have diabetes, local anesthesia might worsen your condition. Adrenaline in anesthetics has a hyperglycemic effect. Your blood glucose levels may surge if you use adrenaline infused anesthetics.

In people with heart conditions

Adrenaline in anesthetics may race your heart. Hence, people with congestive cardiac diseases should avoid anesthetics with adrenaline.

For cases of high blood pressure

Adrenaline has vasoconstrictor action. If you ail from high blood pressure, it is advisable that you don’t use such anesthetics.

Allergic reactions

You may or may not have an allergic reaction to one or more constituents of anesthetics. Hence, it is advisable that you get a patch test every time before this procedure.

Luckily, adrenaline free anesthetics are readily available in every dental office. It is necessary that you let your dentist know if you have any of the conditions mentioned above.

Final words

Depending upon your requirement and extensiveness of a procedure, your doctor administers anesthetics. You remain conscious during the process because local anesthetics do not affect your brain or spinal cord.

You are completely aware of your procedure, yet you feel no pain during the treatment. Here lies the beauty of local anesthetics. Local anesthetics come with their bandwagon of risks.

Hence, give your complete medical history correctly to the clinician before the procedure. Insist on a patch test if you have never undergone this procedure before. That is all you may need to know about local anesthetics.

Romani has done BDS. She is the tooth fairy who is not going to leave a penny under your pillow when you lose a tooth, rather she is going to tell you tales on how not to lose one! She has done BDS.