Dental work — including fillings, crowns and root canals — requires a local anesthetic that may also numb your lips, cheeks and tongue. The numbness can last two or more hours after the procedure. When your mouth and lips are numb, it can be difficult to smile, talk or drink.

Phentolamine mesylate (OraVerse) speeds up the return of normal sensation following dental work. Given as an injection after dental work, studies show that phentolamine mesylate returns normal sensations in the lips, cheeks and tongue faster than without the drug, usually in about an hour. Reversing soft tissue numbness sooner may help to prevent injury, such as accidentally biting your tongue or cheek, and allow you to speak or eat normally.

If a dental procedure, such as surgery, produces soft tissue, nerve or bone pain, phentolamine mesylate may not be recommended. In such cases, the local anesthetic provides prolonged comfort after the procedure.

How phentolamine mesylate works isn't fully understood, but it's thought to increase blood flow to the soft tissue area. It only works if the original anesthetic contains a medication that narrows your blood vessels (vasoconstrictor), such as epinephrine.

Phentolamine mesylate belongs to a class of drugs that can cause low blood pressure, rapid heartbeats and irregular heart rhythms. Though such events are uncommon in reports of phentolamine mesylate use, tell your dentist if you have a history of heart or blood vessel (cardiovascular) disease.

Phentolamine mesylate is not recommended for young children who weigh less than 33 pounds (15 kilograms) and should not be used in children under 3 years old. The use of phentolamine mesylate requires an additional fee and typically isn't covered by dental insurance.