The groundbreaking study is the first to examine the microbiology of periodontal infection and positively connect it to atherosclerosis.

"This is the most direct evidence yet that gum disease may lead to stroke or cardiovascular disease," said Dr. Moïse Desvarieux at Columbia University and lead author of the paper. "And because gum infections are preventable and treatable, taking care of your oral health could very well have a significant impact on your cardiovascular health."

Columbia researchers measured the bacteria levels in the mouths of 657 people who had no history of stroke or myocardial infarction. They also measured the thickness of the subjects' carotid arteries--the arteries that are measured to identify atherosclerosis. The researchers found that people with a higher level of the specific bacteria that cause periodontal disease also had an increased carotid artery thickness, even after taking other cardiovascular risk factors into account.

In the study, atherosclerosis was associated specifically with bacteria that cause periodontal disease, and not with other oral bacteria.

According to Dr. Desvarieux, one possible explanation for the link is that the bacteria that cause the gum disease may migrate throughout the body via the bloodstream and stimulate the immune system, causing inflammation that results in the clogging of arteries.

"It is important that we have shown an association between specific periodontal pathogens and carotid artery thickness that is unique and unrelated to other oral bacteria," said Panos N. Papapanou, D.D.S., Ph.D., director of the Division of Periodontics, Columbia University School of Dental & Oral Surgery, who was also involved in the study.

Ultrasound measurement of carotid artery thickness, which has been shown to be a strong predictor of stroke and heart attacks, was performed without knowledge of the subjects' periodontal health to ensure an unbiased evaluation.

Ongoing study of the patients will determine if atherosclerosis continues over time and is definitively associated with periodontal disease.

New Option to Treat Periodontal Diseases
Periodontal researchers say that photodynamic therapy (PDT) could help suppress the bacteria that lead to periodontal disease.

PDT involves two stages. In the first stage, a light-sensitive drug is applied. The second stage involves shining a light or laser directly on the area treated with the drug. When the light is combined with the drug, phototoxic reactions are induced that destroy bacterial cells. The Food and Drug Administration first approved PDT in 1999 to treat precancerous skin lesions of the face or scalp.

To specifically address periodontal pockets in the mouth, the test tube results are now being verified in several animal and human experiments.