Brushing Up on Oral Hygiene

Experts concur that good dental hygiene is an important tool in managing diabetes.

It’s been called a two-way street, a bidirectional arrow, a loop and a vicious circle.

“It” is the complicated connection between two seemingly unrelated conditions: diabetes and periodontal disease. The reason researchers are beginning to understand it as a not-so-merry-go-round is because not only is poorly controlled diabetes a major risk factor for gum disease, but in turn, untreated gum disease can make diabetes worse or even hasten the progression to diabetes in those at high risk of developing the disease.

But whatever you call this relationship, it’s one that’s not well known or understood.

“I never knew there was a connection between oral care and diabetes. No doctor or dentist ever said anything about it,” says Louise Sherby, 61, a college librarian in New York City. Diabetes runs in Sherby’s family, and three years ago, in the course of testing for minor surgery, she was told she had prediabetes.

Like many people, Sherby had no symptoms. (That lack of signs is one reason a third of the almost 24 million people in this country with type 2 don’t yet know they have it.) “Dental care is prominent for me not because of diabetes but because of a childhood of having lots of cavities,” she adds, “but now I intend to be extra vigilant.”

Bacteria that are normally present in the mouth can produce toxins that irritate the gums, leading to infection and inflammation—and inflammation is mixed up in almost all major chronic diseases, from Alzheimer’s to osteoarthritis. Periodontal disease, which starts in a milder form called gingivitis, is a chronic ailment that eventually can destroy tissues and even bone. Despite its destructiveness, it’s often painless and most people don’t know they have it. Smoking and a genetic predisposition, along with diabetes, can make gum disease worse.

So how can diabetes, a disorder of glucose (blood sugar) control, have anything to do with infection in the mouth?

“People who are diabetic tend not to respond well to infection. Whenever you have bacteria and a reduced ability to fight it, you’re liable to have more disease,” explains Michael S. Reddy, D.M.D., chairman of the department of periodontology at the University of Alabama at Birmingham School of Dentistry. “People with diabetes have worse infections in general for this reason, so their periodontal disease might also be worse.” Think of how you always seem to catch a cold when you’re run-down, and you’ll get the idea of how diabetes diminishes the ability to fight off bugs.

“People who have a healthy immune system can have a mouth loaded with plaque, but their immune system can handle that challenge,” says Casey Hein, B.S.D.H., M.B.A., associate professor in dental hygiene at the University of Colorado School of Dental Medicine and a dentistry faculty member at the University of Manitoba, Winnipeg. “But for a patient whose immune system is not as resilient, a little plaque could send them from gingivitis to periodontal disease.”

And periodontal disease increases the risk of losing teeth, “which is not just a quality of life problem,” notes George L. King, M.D., director of research at Joslin Diabetes Center, Boston, and a professor of medicine at Harvard Medical School. “People who have bad teeth or don’t have teeth (even with dentures) have poor nutrition, which leads to more problems. Nutrition is a huge part of diabetes care.”

Treating the mouth is also an important element of managing diabetes. One small study, of Pima Indians in Arizona who had both advanced gum disease and type 2, found that when their gum problems were treated, their diabetes improved. Dr. Reddy is beginning an NIH-funded study to see if these results hold true for a larger population. “It’s worked in small studies and is promising,” he comments.

Also promising is that dentists and physicians are beginning to keep an eye out for each other’s patients. In general, many who treat type 2 have not emphasized good oral hygiene, even though almost a third of people with diabetes have severe gum disease.

In addition, says Hein, health insurers are considering increasing dental benefits as evidence mounts that good oral hygiene can pay off by reducing more severe medical troubles.

“Most adult periodontal disease can be prevented or fixed. So if there is a dental component to diabetes, then that is one aspect of diabetes we can control,” Dr. Reddy says. “That’s the good news: Good dental care can really make a difference.”