 When you return for the office visit, a dentist or dental hygienist will then collect a sample of your dental plaque a film of mucous and bacteria found on your teeths surface by scraping plaque from the surface of your teeth and flossing between your teeth, and then placing the plaque in a small test tube to check for bacteria. The dentist will not scrape below the gums. These plaque samples will be collected on Weeks 6 and 12 at the dental clinic. 