The inflammatory response is a nonspecific response to cell damage and bacterial invasion. Inflammation is the primary defense in early gingivitis. Biofilm can initiate an inflammatory response if left undisturbed for a minimum of seventy-two hours. Redness and swelling are two of the cardinal signs of inflammation and can be observed clinically in gingivitis. Histamine is released by mast cells and is responsible for the redness and swelling of the tissues. Histamine causes both an increase in vascularity and permeability of blood vessels at the site of injury. Swelling may occur in response to fluid accumulation at a specific site. The inflammatory response includes cellular components of the immune system: polymorphonuclear leukocytes and macrophages. Polymorphonuclear leukocytes are crucial for the cellular immune response. Polyporphonuclear leukocytes are the first cells to arrive at the inflammatory site. Polymorphonuclear leukocytes arrive at the site via chemotaxis and begin to phagocytose the bacteria. As the disease continues and the inflammatory reaction is not strong enough to quell the bacterial infection, the immune response increases