Dental plaque may be "reservoir of respiratory pathogens"

Dec. 2, 2004
Study says better oral hygiene, including good regular toothbrushing, may lessen nursing home residents' chances of developing pneumonia.

Better oral hygiene, including good regular toothbrushing, may lessen nursing home residents' chances of developing pneumonia, according to a study which traced germs from dental plaque to the lungs of patients with the potentially fatal illness.

Dr. Ali El-Solh, lead author of the study published in the November issue of the journal Chest, said the findings "indicate that dental plaque is a reservoir of respiratory pathogens'' that can be inhaled into the lungs and lead to pneumonia.

The University at Buffalo researcher stopped short of saying that brushing or rinsing patients' teeth or dentures is enough to destroy the germs and prevent pneumonia, citing the need for more research. But the study makes a strong case for improving dental care for nursing home residents, he and others said.
Institutionalized and critically ill elderly people, who are often frail with weakened immune systems, are particularly susceptible to pneumonia, and poor dental hygiene has been suspect for several years.

"They tend to have no oral hygiene at all so there's a lot of bacteria growing in the front part of the respiratory tract, the mouth,'' said Dr. Jack Caton, past president of the American Academy of Periodontology, "so it's not surprising that these bacteria can then be somehow inhaled and establish in the lungs and produce pneumonia.''

Caton said other preliminary studies have indicated that cleaning the mouths of patients, either chemically or with toothbrushes or sponges, reduces the incidence of pneumonia, further strengthening the oral health-pneumonia link.

Previous researchers have suggested that oral bacteria contribute to ailments ranging from heart disease to premature births.

The study, funded by a grant from the American Lung Association, followed 49 nursing home patients admitted to the intensive care unit of a Buffalo hospital. The patients' plaque was tested upon admission and the patients were watched for signs of pneumonia.

Fourteen of the patients developed pneumonia while in the hospital. Genetic testing found that the bacteria in the lung fluid of those patients matched the bacteria found in their dental plaque when they were admitted.

"This was a unique study in that they looked at the bacteria before they ever got pneumonia,'' said Dr. Mark Rosen, president-designate of the American College of Chest Physicians.

"This really made the case that the bacteria in the mouth precede those that you see when the pneumonia sets in ... making the case this is how people get pneumonia,'' said Rosen, chief of the Division of Pulmonary and Critical Care Medicine at New York's Beth Israel Medical Center.

The problem will only get worse as the population ages, he said.

"Now the question is, what do you need to do to get rid of the plaque?'' Rosen said. "Is brushing teeth enough? Probably not.''

He said a combination of brushing, flossing and regular dental visits - the same oral hygiene formula recommended for the general population - would likely be most effective.

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