Abstract:

In recent years, there has been growing interest in the systemic implications of periodontal disease and its association with various systemic disorders. Among these is the potential influence of periodontitis on Alzheimer’s disease, the leading cause of dementia in the elderly population worldwide.

Periodontal pathogens, grouped into the Socransky complexes, have been the focus of extensive studies over recent decades. The bacteria of the red complex (P. gingivalis, T. denticola, and T. forsythia) exhibit cooperative behavior within the dental biofilm and are directly associated with the progression of periodontal destruction. Concurrently, three key pathogenetic mechanisms of Alzheimer’s disease are under active investigation: beta-amyloid accumulation in the brain, tau hyperphosphorylation and microglial activation.

Recent studies indicate the potential for bacteria within the red complex to impact all of these mechanisms. Although the existence of a direct causal link between periodontal disease and Alzheimer’s disease remains a topic of debate, growing evidence suggests a correlation between these diseases.

The objective of this review is to present the existing scientific literature on the impact of each of the red complex pathogens on the pathogenetic mechanisms of Alzheimer’s disease.

Keywords: Alzheimer’s disease, periodontal pathogens, periodontitis