Sometimes your dentist needs to numb a part of your mouth. He or she injects medicine into your gum or inner cheek. This medicine is called local anesthesia.

Lidocaine is the most common local anesthetic that dentists use. There are many others. They all have names ending in "-caine." Many people think of Novocain as the classic numbing drug. But Novocain actually is not used anymore. Other drugs last longer and work better than Novocain. These drugs also are less likely to cause allergic reactions.

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