**Neutrophil Role in Periodontal Disease**

Carlos Rosales and Eileen Uribe‐Querol

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/67789

#### **Abstract**

Oral tissues are constantly exposed to damage from the mechanical effort of eating and from the invasion of foreign microorganisms such as bacteria, fungi, and virus. In healthy oral tissues, there is a balance between symbiotic bacteria and cells from the innate immune system, mainly neutrophils. When this balance is broken, inflammation appears and more immune cells are recruited to the gingiva. Neutrophils form a barrier against dysbiotic bacteria. However, when neutrophils are insufficient, bacteria thrive causing periodontitis, a chronic inflammatory disease that destroys the tooth‐supporting tissues or periodontium. Damage of periodontal tissues leads to tooth loss, and in severe cases, it can also affect systemic health by increasing a person's risk for atherosclerosis, rheumatoid arthritis, diabetes, and even cancer. The mechanisms neutrophil employ to keep a balance with bacteria in order to maintain healthy oral tissues is the focus of this chapter. We discuss how neutrophil antimicrobial functions keep bacteria at check and how some dysbiotic bacteria block neutrophils to promote an inflammatory state. Also, novel therapeutic approaches for periodontitis are discussed.

**Keywords:** neutrophil, phagocytosis, degranulation, NETs, oral microbiota, dysbiotic microbiota
