Association between periodontitis and Alzheimer's disease: A narrative review

Periodontitis is a chronic inflammatory disease that progressively damages the supporting structures of teeth, resulting in gum bleeding, inflammation, gum recession, and eventual tooth loss. Key factors, including poor oral hygiene, plaque accumulation, smoking, inadequate nutrition, and genetic predisposition, drive its development. Recent evidence underscores the potential role of periodontitis as a contributing factor to systemic diseases, including Alzheimer's disease (AD). AD is a neurodegenerative disorder marked by memory loss, cognitive decline, and brain inflammation. Emerging clinical and experimental studies indicate that these two conditions share overlapping risk factors and may be interconnected. One notable finding is the detection of specific periodontal pathogens, such as Porphyromonas gingivalis (P. gingivalis), in the brains of individuals with AD. This suggests a possible link between chronic oral infections and neurodegeneration. These pathogens are believed to exacerbate neuroinflammatory processes by activating microglia and promoting systemic inflammation, which is central to AD pathogenesis. Further research is needed to clarify the biological mechanisms underlying this association. Targeted interventions that address periodontitis, such as anti-inflammatory therapies or treatments targeting specific pathogens like P. gingivalis, could potentially mitigate its impact on the onset and progression of AD, offering a novel avenue for prevention and management strategies.