9/30/2002

SAN DIEGO, Sep 28, 2002 (United Press International via COMTEX) -- Brushing and flossing may do more than give you a bright smile, it may also help prevent heart disease, microbiology experts said Saturday.

Caroline Genco of Boston University's medical school said infecting mice with the microbe that causes periodontal disease more than doubles the amount of blockage in their arteries, compared with uninfected mice.

Genco said the study, presented the Interscience Conference on Antimicrobial Agents and Chemotherapy, is the first clear evidence that preventing or curing periodontal disease -- known in its less severe form as gingivitis -- also can reduce the inflammation that leads to such ailments as atherosclerosis.

Periodontal disease, which is caused by a microbe called porphyromonas gingivalis, is common among people over 40, and often begins colonizing the human mouth around the age of 12 or 13, Genco said.

Genco told United Press International the study has a clear message, even before more research ties down the link between the mouth and the arteries. "Go to your dentist and be treated for this disease," she said.

Periodontist Thomas Van Dyke, a biomedical researcher at Boston University's dental school, said there have been many studies that found a link between periodontal disease and such different problems as cardiovascular disease, diabetes and low-birth-weight babies.

Those studies, however, he said, didn't demonstrate a cause and effect relationship between the microbe and the diseases.

"The significance of (Genco's) study is that it's the first step toward showing there is a cause-effect relationship," Van Dyke told UPI.

Genco took mice, specially bred for a tendency to develop heart disease, and infected their mouths with the gingivitis microbe. Other mice of the same type were infected with a closely related microbe that does not cause disease, and still others were left alone.

After 17 weeks, she said, the mice with gingivitis had 2.5 times the amount of fatty build-up in their arteries as did either of the other two groups of mice.

Because it's in the mouth, which often suffers minor cuts and abrasions, the microbe can easily get into the bloodstream, Genco said, where it causes inflammation in the arteries. It's that inflammation that leads to the build-up of fatty deposits that block the arteries and lead to cardiovascular disease.

Genco added other bacteria also may cause inflammation that leads to cardiovascular disease, but the gingivitis microbe is important because it's common.

She added by the time periodontal disease is serious enough for people to seek help -- especially those who don't regularly see a dentist -- it may be tool late -- the microbe may already be inflaming the blood vessels.

"You need to practice early oral hygiene," Genco said, and added there is no vaccine to combat the gingivitis microbe.