MADRID –
The Spanish Society of Dentistry and Osseointegration (SEPA) and the Spanish Society of Neurology (SEN) recently released a report with the latest data on this topic. The report reviews, updates, and presents the most recent scientific evidence regarding this link. It also provides practical recommendations that, on the basis of the evidence, should be applied in dental clinics and neurology centers.
As Yago Leira, DDS, PhD, periodontist and coordinator of the SEPA-SEN working group, told this news organization, “The main takeaway from this scientific report is that patients with periodontitis are at nearly twice the risk of developing Alzheimer’s disease and at triple the risk of ischemic stroke.”
Data from the report show that individuals with periodontitis are at 2.8 times’ higher risk of ischemic stroke. The available evidence regarding hemorrhagic stroke, however, is conflicting.
How does this dental condition affect the course of cardiovascular disease? Observational studies have shown that those who have had an ischemic stroke and have a confirmed diagnosis of periodontitis are at greater risk of suffering a recurrent vascular event, worse neurologic deficit, and postictal depression than are patients without periodontitis.
Immune‐mediated inflammation
As far as its link to Alzheimer’s disease, meta-analyses of epidemiologic studies show that periodontitis is associated with a 1.7 times greater risk of this type of dementia and that the risk triples among patients with more serious forms of periodontitis.
Likewise, studies suggest that individuals with dementia or neurocognitive impairment are at a greater risk of suffering periodontitis. Other studies indicate that individuals with periodontitis have worse outcomes on various neuropsychological tests of cognitive function.
The current report presents the evidence from three clearly defined perspectives: The epidemiologic association between periodontitis and these neurologic diseases, the biological mechanisms that may explain this link, and interventional studies of dental treatment as a means of preventing stroke and Alzheimer’s disease.
“There is a possible biological explanation for these epidemiological findings. The report concludes that the low-grade chronic, systemic, immune-mediated inflammatory response induced by the bacteria and their endotoxins and the proinflammatory mediators circulating through the blood contributes to various biological processes that are involved in neurological impairment and cerebral ischemia,” said Dr. Leira, one of the report’s authors.
Ana Frank, MD, PhD, another author of this study, is head of the neurology department at the La Paz University Hospital in Madrid and a member of the SEPA-SEN group. She said in an interview that the main biological mechanism in stroke and Alzheimer’s disease is chronic exposure of the entire brain (vasculature, neurons, and astrocytes) to the harmful effects of periodontal infection. “Although low in intensity, this [exposure] is sufficient to set off a series of events that eventually lead to vascular endothelial injury, changes to neurons and astrocytes, and damage to the neuropil.”
As far as the evidence of an epidemiologic association between periodontitis and both neurologic diseases, Dr. Frank cited the exponential increase in risk brought on by periodontitis. She said that further epidemiologic studies are necessary to gain a better understanding of the magnitude of the problem.