Periodontitis is the most prevalent chronic infectious inflammatory disease in adults, leading to the destruction of tooth-supporting tissues. Beyond its local impact, periodontitis contributes to systemic inflammation through the release of periodontal pathogens and their byproducts into the bloodstream. Given that chronic intracerebral inflammation is a known driver of Alzheimer's disease (AD) progression, a biological link between the two conditions has been hypothesized. This study aims to evaluate whether periodontal treatment can influence AD progression by reducing systemic inflammation. We have designed a randomized controlled clinical trial including 70 patients diagnosed with both AD and stage 3 or 4 periodontitis, randomly allocated to receive either immediate (test group) or delayed (control group) periodontal therapy. All participants will undergo comprehensive periodontal treatment and be followed over a 24-month period. Cognitive assessments, periodontal evaluations, blood and saliva biomarker analyses, and neuroimaging will be conducted at multiple time points to assess the potential impact of periodontal therapy on AD progression. This trial represents the first clinical investigation into the effect of periodontal treatment on the course of Alzheimer's disease.