How do you get rid of the numbness feeling from a novocain (procaine) shot?

Wait. The numbness from an anesthetic injection should go away on its own within 2 to 8 hours. If the numbness doesn't go away, see your doctor.
Not much you can do. Length of anesthesia can vary depending on a variety of factors usually 1-2 hours. May be prolonged if used with other meds. Dr l.