Examining periodontal disease as a possible risk factor for Alzheimer's disease

Thesis (M.A.)--Boston UniversityPLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you.Studies have revealed an association between periodontal disease and a number of systemic diseases, including atherosclerosis and diabetes. These findings may help physicians identify correctable causes of disease early in the course of progression or prevent disease onset entirely. As the number of possible systemic diseases associated with oral infection is being explored and expanded, cognitive impairment associated with dementia has been added to the list as a possible end organ target. This paper examines the available research focused on exploring this potential link between Alzheimer's disease and periodontal disease. Alzheimer's disease and periodontal disease are both major public health concerns that most commonly affect the elderly population. Recently, several cross-sectional studies have investigated the oral health status of individuals with Alzheimer's disease, finding that often these individuals are not able to take care of their own oral needs. This has alerted healthcare professionals and caretakers to the need for more focused attention to oral health in this population. Conversely, a small number of studies have also set out to investigate the role of pre-existing poor oral health in the development of Alzheimer's disease. The mechanisms and evidence recently published on this possible bi-directional link are reviewed in this paper. The central focus is on the role of inflammation in the central nervous system of patients with Alzheimer's disease. It is believed that chronic diseases, such as periodontal disease, can cause systemic inflammation by directly introducing bacterial pathogens, toxins, and other inflammation inducing substances into the bloodstream. Some of these studies have used detection methods to determine the presence of oral pathogens in distant body parts, including the brain. Several bacteria identified in these sites are major periodontal pathogens, which have also been linked to other systemic diseases such as atherosclerosis. Other studies have focused their research on the detection of inflammatory markers and endotoxins associated with pathogens involved in oral infection. Some studies have also indicated a significant correlation between lifetime tooth loss and impaired cognition later in life. Future research must continue to examine how periodontal pathogens and inflammation contribute to the pathology in AD, and whether the two diseases merely share common risk factors or are interrelated. Potential confounders including viral infections, head injury, low socioeconomic status, malnutrition and genetic inflammatory susceptibility must also be controlled for ill order for the results to be more conclusive While there is evidence indicating that a bidirectional link may exist between AD and periodontal disease, at this point there is still not enough evidence to establish this conclusively. Still, the studies presented here do serve as an important foundation for future research; such as randomized-controlled intervention trials with long term followup that would help elucidate causation. The results of these preliminary investigations are certainly promising enough to warrant these future studies to determine if preventative oral health measures could potentially reduce the risk of developing AD.2031-01-0