Alzheimer's disease and chronic periodontitis: is there an association?

Alzheimer's disease, an affliction of old age, is one of the leading causes for dementia worldwide. Various risk factors including family history, genetics and infections have been implicated in its pathogenesis. The cognitive decline in this condition is mainly a result of the formation of amyloid deposits that provoke neuroinflammation, ultimately resulting in cell death. Recently, an association between peripheral inflammation and Alzheimer's disease was hypothesized. It was suggested that chronic systemic inflammation worsened the inflammatory processes in the brain. This was mainly attributed to increased levels of pro-inflammatory mediators, such as interleukin-1, interleukin -6 and tumor necrosis factor-α in the plasma. As chronic periodontitis is a widespread peripheral immunoinflammatory condition, it has been proposed to play a significant role in the aggravation of Alzheimer's disease. With this background, the current review focuses on the relationship between Alzheimer's disease and chronic periodontitis, and its therapeutic implications.