Dental numbing usually lasts 1 to 3 hours, and sometimes up to 5 hours.
Duration
Dental numbing from lidocaine usually lasts 1 to 3 hours. The lips and tongue can remain numb up to 5 hours.
By drug
- Lidocaine with epinephrine: 3 to 5 hours of soft tissue numbness.
- Articaine: 2 to 4 hours.
- Bupivacaine: 6 to 8 hours.
Factors
Dose, injection site (lower jaw lasts longer) and metabolism.
Tips
- Don’t eat until it wears off.
- Avoid hot drinks.
- Don’t bite your lip or cheek.
- Light activity may speed up blood flow.
Reversal
Phentolamine (OraVerse) can shorten it.
Call your dentist
If numbness lasts more than 12 hours.
How the numbness works
Dental anesthetics block sodium channels in nerves so pain signals do not reach the brain. After the injection, the drug is slowly carried away by the blood and broken down by the liver and plasma enzymes, and feeling returns. Epinephrine added to most solutions narrows blood vessels, keeping the drug in the area longer.
Duration in detail
Typical soft tissue numbness lasts about 2 to 4 hours, and in some cases up to 5 to 6 hours, with a longer duration for the lower jaw. Pulp (tooth) numbness is shorter, from 30 to 90 minutes. Strength and length depend on the product and dose. Most dentists place one to three cartridges, each 1.7 or 1.8 milliliters.
By drug
- Lidocaine 2% with epinephrine: tooth 60 minutes, soft tissue 3 to 4 hours.
- Articaine 4% with epinephrine: tooth about 60 to 75 minutes, soft tissue 3 to 5 hours, and it spreads well through bone.
- Mepivacaine 3%: tooth 20 to 40 minutes, soft tissue 2 to 3 hours.
- Bupivacaine 0.5%: tooth 90 to 180 minutes, soft tissue up to 8 to 9 hours.
Factors
- Injection site and type: lower jaw blocks last longer.
- Your metabolism and age.
- The dose and the drug’s concentration.
- Infection or inflammation in the area, which makes anesthetics less effective.
- Use of phentolamine reversal.
Tips
- Do not eat until feeling returns to avoid biting your lip or tongue. Parents should watch children closely. Lip biting is a leading cause of injury after dental visits.
- Drink cool liquids, with care.
- Walk and be active, as increased circulation may help, though evidence is limited.
- Take pain relief as advised before numbness wears off.
Reversal
Phentolamine mesylate (OraVerse), given at the end of the procedure, reduces numbness duration by about half for lip and tongue, and is approved for patients 3 years of age and older who weigh at least 15 kg.
Call your dentist
Call if numbness lasts more than 12 to 24 hours, if you have constant tingling, a burning sensation, or loss of taste, or if you notice swelling, rash or breathing problems. Persistent nerve symptoms are rare but need prompt evaluation.
Local anesthetic types and timelines
Dental numbness comes from local anesthetics such as lidocaine, articaine, mepivacaine and bupivacaine that block sodium channels in nerves. Soft tissue numbness of the lips and tongue typically lasts 2 to 4 hours, while pulp numbness in the tooth lasts about 1 to 2 hours for lidocaine with epinephrine. Bupivacaine can last 6 to 8 hours and is used for longer procedures. Lower jaw blocks last longer than upper jaw infiltrations. Adding epinephrine constricts blood vessels and extends the effect. Avoid hot drinks and chewing until feeling returns, since biting the cheek or tongue is a common injury, especially in children. A reversal agent called phentolamine mesylate (OraVerse) can shorten soft tissue numbness by about half. Contact the dentist if numbness lasts more than 24 hours, or if you have swelling, trouble breathing or a rash.
Based on data from the American Dental Association and the NIH
