Most local anaesthetics will numb your teeth for 2-3 hours following the injection, while your lips and tongue will be numb for 3-5 hours. The numb sensation will gradually fade away as blood flow transports the anaesthetic from the injection site to be metabolized or broken down. Some nerves may never recover full function after undergoing anaesthesia. After a tooth is removed, you may experience some pain due to damage caused by the extraction procedure itself. This type of pain usually goes away within a few days and does not need any special treatment. Any other symptoms that may occur after the anesthesia has worn off are most likely due to problems associated with the nerve damage occurring during the extraction process. If you are having severe pain beyond what can be managed with ordinary means, then it might be time to call your dentist. They may be able to advise you on how to manage the pain longer term through the use of medications or new techniques. However, it is important to note that prolonged use of analgesics can lead to side effects such as dizziness, nausea, and drowsiness. In some cases, the extraction site may become infected. If this happens, you will need to see your dentist right away so that the problem can be resolved quickly before any further damage occurs.