 During the establishment of a periodontal disease, an important inflammatory infiltrate is observed in the gum. This infiltrate is characterized by the presence of many B lymphocytes. B cell subsets in the blood and the gum of patients with periodontitis have been little studied. However, the number of autoreactive B cells cluster of differentiation CD19, CD5 has been reported to be higher in the blood of patients with periodontal disease. In the gum, the rate of B and T cells increases with the level of inflammation and is correlated with the severity of the inflammatory process. Activation of B cells is a prerequisite for the progression of gingivitis to periodontitis. B cell distribution could then be an indicator of disease progression, but also allow to study the response to treatment. 