How long does dental numbing last?

How long does numbing last?

Cleveland Clinic says the effects of common dental anesthetics such as articaine and lidocaine should go away completely within about two hours, and that mepivacaine wears off sooner. Healthline's guide to eating after a filling says local anesthetic usually wears off in one to three hours but can last longer depending on the type and amount used.

Older sources describe procaine, sold as Novocaine, as shorter-acting. Healthline's Novocaine guide says it typically lasts 30 to 60 minutes, about 90 minutes with epinephrine added, and that lidocaine lasts longer, about an hour and a half to two hours. Most dentists today use other anesthetics, so treat two hours as a typical figure rather than a promise.

What makes numbness last longer

Both Cleveland Clinic and Healthline name the same main factors.

• Dose: higher doses, multiple injections or extensive procedures can prolong numbness, because a dentist may give more to keep an area numb for longer.
• Type of anesthetic: articaine and lidocaine last longer than mepivacaine.
• Epinephrine: adding it extends the effect.
• Where it was given: numbness depends on the injection site, and you may lose feeling in your lips, cheek or face as well as the tooth.
• The person: effects vary slightly between people.

Can you make numbness wear off faster?

No, not on your own. Cleveland Clinic says there is no way to speed it up by yourself: you have to wait for the medication to leave the tissue. Some dentists can give a reversal injection (phentolamine, sold as OraVerse), which Cleveland Clinic's drug information says reverses the effects of numbing medicines in the mouth, so ask your dentist beforehand if a long period of numbness would be a problem for you. The sources we read do not recommend any trick.

Healthline notes that a rare genetic condition called pseudocholinesterase deficiency, which it says affects about 1 in 5,000 people, makes it harder to break down procaine, so effects may last much longer. If you know you have it, tell your dentist before treatment.

Eating and drinking while numb

Cleveland Clinic lists biting your lip, cheek or tongue among the side effects of being numb and says to take care while chewing or talking. Healthline's guide to eating after a filling says to wait until the numbness wears off before eating, which usually takes one to three hours, and to avoid hot items, because you cannot feel a burn. If you must eat, choose soft food, take small bites and chew slowly on the side that is not numb.

Drinking can be messy while numb, so use a cup and sip slowly. Our guide on eating after a filling covers what to eat first.

What you may feel as it wears off

Healthline says tingling and soreness may occur as numbness wears off, along with mild, short-lived effects such as pins and needles, headache, dizziness, drowsiness, muscle twitching and minor pain at the injection site. Cleveland Clinic says soreness at the injection site can linger.

Allergic reactions to dental anesthetic are exceedingly rare, according to Healthline, but the signs are itching, hives, difficulty breathing, facial or hand swelling and loss of consciousness. Those need emergency care.

Numbness after wisdom tooth removal

After surgery, a longer period of numbness can be normal if sedation or a nerve block was used, but the NHS recovery page lists nerve damage causing numbness or tingling in the tongue, lips or chin as a possible complication. It does not give a time cut-off, and neither does Cleveland Clinic's numbing page, which does not address numbness lasting beyond about two hours. If numbness is clearly longer than you were warned about, or is spreading, call the practice that treated you.

Questions to ask before treatment

A short conversation at the start removes most of the guesswork.

• How long should I expect numbness to last for this procedure?
• Is the area going to include my lip, tongue or cheek?
• Are there medicines or health conditions you should know about?
• When is it safe to eat and drink afterwards?
• Who should I call if numbness lasts longer than expected, and what is the number outside office hours?

Frequently asked questions