Alzheimer’s disease (AD) seen in the aging population worldwide, is the most frequent type of dementia characterized by a progressive decline in memory. This systematic review was conducted based on the indications of the Prisma protocol. The formulation of the PICO question was as follows; what is the etiopathogenetic role of periodontal disease and periodontal bacteria in the onset and progression of Alzheimer’s disease compared to unaffffected patients? After an initial selection phase of the records identifified from the databases, the potentially eligible articles were qualitatively evaluated to investigate the role of periodontal disease bacteria. The literature search was conducted on the search engines PubMed, Scopus and Web of science between 10.09.2000 and 02.09.2022. With the application of the eligibility criteria, there were 397 articles. There were 89 articles that discussed the role of periodontal bacteria in the onset and progression of Alzheimer’s disease; there were 28 articles after eliminating overlaps. After applying the inclusion and exclusion criteria, the result was a total of 7 articles for the qualitative analysis. Although the host–pathogen interaction appears to be a key factor in the pathogenicity of periodontitis, as to how periodontal disease can impact or translocate to the brain remains poorly understood.