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30 August 2016

How long does the anesthetic last after a dental injection?

A local anaesthetic is a medication used to numb you from feeling any kind of sensitivity and pain during and until a few hours after root canal procedure. It doesn’t make you lose consciousness, but it effectively relieves you from pain. You may only feel slight pressure or movement. Local anaesthetic works by blocking the nerves from the affected parts of the body so that pain signals would not reach your brain.

A local anaesthetic is injected or applied on the area the dentist needs to work on—the gums, the inside of the cheek, affected tooth, etc. Upon administration of local anaesthetic, it will only take a few minutes for you to lose sensation in the area where it is injected or applied. Your dentist will make sure that the area is completely numb before starting the procedure. With most local anaesthetics, your tooth will be numb for 2-3 hours, while your lips and tongue will be numb for 3-5 hours after the time of injection. As the blood flow carries away the anaesthetic from the injection site to be metabolized or broken down, the numb feeling will gradually fade away. During this time, it is important not to sustain any damage to the numb area. One of the reasons why you are told to rest and take it easy after any procedure administered with an anaesthetic is because being active or engaging in any form of strenuous physical activity makes the anaesthetic effects fade more quickly. Your dentist Richmond may prescribe you painkillers especially if it’s likely you’ll feel a lot of pain after the anaesthetic wears off.

Lidocaine is a common local anaesthetic used in dental procedures. There are many others, most of them ending in –caine. Many of these drugs are less likely to cause allergic reactions. Local anaesthetic includes not just the numbing part of the liquid being injected or applied to you, but may also include the following:

  • Epinephrine (adrenaline) – This is added to the anaesthesia solution to increase its numbing effect.
  • Vasoconstrictor – This narrows your blood vessels and makes the numbness last longer.
  • Sodium chloride – This allows the drugs to be absorbed into your blood.
  • Sodium hydroxide – This makes the numbing drug work.

Local anaesthesia with epinephrine is commonly used. Its numbing effect lasts for 2-4 hours, and in some cases, until after a few days. It is important to note that patients who have heart disease, high blood pressure, or have allergic reactions to epinephrine inform their condition to their dentist before root canal procedure. They will be administered with a local anaesthetic without epinephrine. The numbing effect of local anaesthetics without epinephrine usually last an hour or less than two hours after administration.

Shortly after being administered with a local anaesthetic, you may experience side effects, but in most cases, these are minor and temporary and do not cause long-lasting problems. Side effects include:

  • a numb tongue, tooth, or mouth.
  • drowsiness.
  • dizziness.
  • blurred vision.
  • twitching muscles.
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