NEUTROPHIL IN PERIODONTAL HEALTH AND DISEASE

Neutrophils are the most abundant leukocytes in blood and are considered to be the first line of defence during inflammation and infections. Neutrophils, are myeloid-derived, antimicrobial phagocytes. The polymorphonuclear leukocyte is the most important phagocytic cell in the defence of the host against acute bacterial infection. During bacterial invasion, microorganisms evoke an inflammatory response that recruits neutrophils from the circulation into the tissues. Therefore, neutrophils destroy the microorganisms by a series of mechanisms, mainly phagocytosis, release of antimicrobial substances, and the formation of neutrophil extracellular traps (NETs). Activated neutrophils also release proteinases into the surrounding tissue, causing damage to the host. Neutrophils are granulocyte which form essential component of the cellular innate system involved in killing bacteria and fungi. They play critical role in host defence by phagocytizing and digesting microorganisms and inappropriate activation of neutrophils may result in damage to normal host tissue.