A dental numbing shot, or local anesthetic, is a common part of many dental procedures. Its primary purpose is to block pain signals in a specific area of your mouth, ensuring comfort during treatments like fillings, root canals, or extractions. The numbing effect is temporary, and its duration can vary.
Expected Numbing Period
The duration of numbness from a dental shot varies by area. For the tooth, it often lasts two to three hours. Surrounding soft tissues like lips, tongue, and cheeks generally remain numb longer, usually three to five hours. Overall, most patients can expect the sensation to persist for one to four hours after a routine procedure.
The anesthetic typically begins to work within minutes, quickly numbing the targeted area. This ensures the area is numb before treatment. As the body metabolizes the anesthetic, the numb feeling slowly fades.
Variables Affecting Numbing Duration
Several factors can influence how long a dental numbing shot lasts. The type and amount of anesthetic administered play a significant role. For instance, Lidocaine, a commonly used anesthetic, typically provides numbness for one to three hours, while Articaine might last two to four hours. The addition of epinephrine, a vasoconstrictor, can extend the numbing effect by constricting blood vessels and slowing the anesthetic’s absorption from the injection site.
The location of the injection also impacts duration. Numbing near major nerves, such as those in the lower jaw, often lasts longer because the anesthetic diffuses more slowly in these areas. Conversely, areas with higher blood flow tend to absorb the anesthetic more quickly, potentially leading to a shorter numbing period. Individual metabolism is another important factor, as each person’s body processes medications at a different rate, affecting how quickly the anesthetic wears off.
Individual metabolism, influenced by factors like age, weight, and overall health, also affects how quickly the anesthetic wears off. The presence of infection or inflammation in the treated area can reduce the anesthetic’s effectiveness or duration. Complex procedures may require higher doses or additional injections, which can extend the numbing effect.
After the Numbing Fades
As dental numbing wears off, sensation gradually returns. You might first notice tingling, itching, or slight discomfort. This return of feeling signifies the anesthetic is leaving your system and nerve signals are reactivating.
While numb, take precautions to avoid biting your lips, cheeks, or tongue, as you won’t feel injury. Wait until full sensation returns before eating solid foods or hot beverages. If you must eat while numb, choose soft foods and chew carefully to prevent injury. Over-the-counter pain relievers can manage any residual soreness.
When to Seek Dental Advice
While numbness after a dental shot is normal, certain situations warrant contacting your dentist. If numbness lasts significantly longer than expected (e.g., beyond eight to twelve hours), contact your dental office. Prolonged numbness, though rare, could indicate a potential issue.
Contact your dentist if you experience severe pain, excessive swelling, or unusual discharge around the treated area. These symptoms might suggest an infection or other complication. Any signs of an allergic reaction (e.g., rash, itching, difficulty breathing) require immediate medical attention. Persistent tingling, weakness, or altered sensation that doesn’t resolve within a few days should also be reported, as these could be symptoms of nerve injury.