How long does dental anesthesia wear off?

From the Guidelines

Dental anesthesia typically wears off within 1-5 hours, depending on the type used, with local anesthetics like lidocaine lasting 1-2 hours for soft tissue and 3-5 hours for numbness in the lips, cheek, and tongue 1. The duration of dental anesthesia varies based on several factors, including:

• The specific medication used, such as lidocaine, mepivacaine, or bupivacaine
• Whether a vasoconstrictor like epinephrine was added, which can prolong the effect
• The injection site, with different areas of the mouth having varying durations of numbness
• Your individual metabolism, which can affect how quickly the anesthesia is broken down
• The dose administered, with higher doses potentially leading to longer-lasting numbness Some common local anesthetics and their durations of action are:
• Lidocaine (with epinephrine): 1-2 hours for soft tissue, 3-5 hours for numbness in the lips, cheek, and tongue
• Mepivacaine: 30-60 minutes
• Bupivacaine: 4-9 hours It's essential to follow your dentist's instructions and take precautions to avoid injury while still numb, such as avoiding hot foods, chewing gum, or biting your cheek 1. If numbness persists beyond 24 hours, it's crucial to contact your dentist, as this could indicate nerve damage, although this complication is rare.

From the FDA Drug Label

The onset of action following dental injections is usually 2 to 10 minutes and anesthesia may last two or three times longer than lidocaine and mepivacaine for dental use, in many patients up to 7 hours. Patients receiving dental injections of Bupivacaine Hydrochloride should be cautioned not to chew solid foods or test the anesthetized area by biting or probing until anesthesia has worn off (up to 7 hours)

The dental anesthesia from bupivacaine can last up to 7 hours after administration. Patients should be cautious not to chew solid foods or test the anesthetized area until the anesthesia has worn off. 2 2

From the Research

Duration of Dental Anesthesia

• The duration of dental anesthesia can vary depending on the type of anesthetic used, with some studies suggesting that bupivacaine can provide longer-lasting anesthesia compared to lidocaine 3, 4.
• A study comparing the anesthetic efficacy of lidocaine and bupivacaine in impacted third molar surgery found that the duration of action was longer in the bupivacaine group than in the lidocaine group (p = 0.00002) 3.
• Another study found that the use of a long-term anesthetic (bupivacaine) over a short-term one (lidocaine) in awake carpal tunnel release surgery decreases postoperative pain over the initial 12 hours after surgery and delays the initiation of analgesic consumption 4.

Factors Affecting Anesthesia Duration

• The type of procedure being performed can also affect the duration of anesthesia, with some studies suggesting that bupivacaine may be more effective in controlling pain after periodontal flap surgery 5.
• The dosage and concentration of the anesthetic can also impact the duration of anesthesia, with higher doses and concentrations potentially leading to longer-lasting effects 6, 7.
• Individual patient factors, such as age and overall health, can also influence the duration of anesthesia, although more research is needed to fully understand these factors 3, 4.

Comparison of Anesthetic Agents

• Studies have compared the efficacy and safety of bupivacaine and lidocaine in various procedures, including dental and nasal surgeries 3, 4, 7.
• A meta-analysis found that bupivacaine was better than lidocaine in controlling postoperative pain, while lidocaine was better at managing pain during transnasal endoscopic examinations 7.
• Another study found that liposomal bupivacaine did not reduce pain to manageable clinical levels in patients presenting with untreated, symptomatic irreversible pulpitis, although it did provide some effect on soft tissue anesthesia 6.