When U.S. Army reserves are called up for duty in Iraq, the No. 1 cause for delaying their deployment is poor oral health.

There’s no sense in sending a soldier to a war zone, after all, if he’s going to be sidelined with an infected tooth as soon as he gets there, said Dr. Dushanka Kleinman, chief dental health officer for the U.S. Public Health Service. Many reservists therefore must undergo restorative dental work before they can ship out.

It’s not a new concern. Oral health problems have been the leading cause of delayed deployments since World War II, said Kleinman, one of more than 600 oral health specialists attending the National Oral Health Conference this week at the Omni William Penn Hotel, Downtown.

But the fact it is nothing new is not reassuring. The nation’s oral health isn’t getting any worse, Kleinman said yesterday, but it isn’t getting much better either.

“We think the problem is invisible,” she said at a press briefing, noting some of the worst problems occur among the urban poor and in isolated rural areas, where both water fluoridation and dentists can be hard to find. Much of society thus lacks awareness of the problem.

The number of people covered by dental insurance has been increasing, she acknowledged, but about 100 million Americans remain without any coverage — more than twice as many as lack health coverage. Medicare pays for few dental procedures — even though the elderly are particularly at risk for dental problems and oral cancers — and state Medicaid coverage is spotty.

Dr. Robert Weyant, chairman of dental public health at the University of Pittsburgh School of Dental Medicine, said the dental school runs an aggressive outreach program in Western Pennsylvania, applying protective dental sealants to the teeth of second-graders at schools with large percentages of underserved children. The school also sponsors oral cancer screenings at Giant Eagle supermarkets and at senior recreation centers.

But the reach of those efforts is limited, particularly east of Pittsburgh, Weyant acknowledged, and dental providers are scarce in many rural areas of the state.

Dr. Lewis Lampiris, president of the Association of State and Territorial Dental Directors, noted that about a third of Americans still do not drink fluoridated water, the most effective public health measure for improving oral health. Only about half of Pennsylvanians drink fluoridated water.

“It’s a struggle all the time to get fluoride into the water systems,” agreed Dr. Richard Haught, president of the American Dental Association.

Kleinman emphasized that good oral health care is about more than simply filling cavities. In addition to detecting oral cancers associated with tobacco use, oral examinations can also reveal early symptoms of diabetes, HIV and other diseases.

Anita Boles, executive director of the National Healthy Mothers, Healthy Babies Coalition, noted that preliminary studies suggest that pregnant women with gum infections are seven times more likely to give birth prematurely than pregnant women with good oral health. Kleinman said clinical studies are now under way to confirm the link between prematurity and periodontal disease.