Antibiotic Treatment Effects on Intratumoral Bacteria Modulation in Surgical Patients With Oral Cancer

This study investigates whether a short course of antibiotics (metronidazole) and an antiseptic mouth rinse (chlorhexidine) given before surgery can change the bacteria living inside oral cancer tumors, and whether that change affects surgical outcomes and cancer biology. **You may be eligible if...** - You are 18 or older - You have been diagnosed with squamous cell carcinoma of the mouth (oral cavity) - You are scheduled to have surgery with the intent to cure - You are able to understand and sign an informed consent form **You may NOT be eligible if...** - You have a known allergy to metronidazole or chlorhexidine - You have severe liver or kidney disease - You are actively drinking alcohol or cannot abstain during the 10-day antibiotic period - Your oral cancer is a recurrence after prior radiation or chemoradiation - Your cancer is not surgically removable Talk to your doctor to see if this trial is right for you.