If a medical procedure requires you to have a sedative in addition to a local anesthetic, you should not eat beforehand. If the procedure does not require a sedative, there are generally no restrictions in regard to food. However, it is always best to verify instructions with your doctor.
Side effects occur less often from local anesthetics in comparison to procedures using a general anesthetic, but some cases may require the use of a sedative. When a doctor uses a sedative, side effects such as headache, dizziness and vomiting may occur, so they generally recommend that patients refrain from eating or drinking prior to the procedure. This can reduce the risk of complications such as aspiration, or inhaling stomach contents into the lungs.