This is a medical test that helps to detect whether the growth of abnormal tissues is cancerous or not. The test is conducted basically by removing a bit of gum cells and then putting it under the laboratory microscope to detect any abnormalities. There is not much preparation needed for biopsy to occur, however, you should discuss all the medications with your dentist. This would help them to understand your case better. Before the process starts your dentist would suggest you stop eating before few hours.