In Northern Virginia, 16 percent of lower-income adults have not gone to a dentist in more than five years, according to a report that looks at disparities in oral health in one of the most prosperous regions in the country.

Among lower-income adults who have health coverage, only one-fourth have coverage that includes dental care, compared to 64 percent for higher-income adults.

Those were among the key findings in a survey of oral health in Northern Virginia released Thursday. The survey was commissioned by the Northern Virginia Health Foundation, a nonprofit group that focuses on health-care safety nets.

“For people with limited means and no insurance, routine dental care is often out of reach,” said Patricia Mathews, president of the Northern Virginia Health Foundation. “Because of costs, they are more likely to suffer severe pain from untreated dental problems, miss time from work or school, or wind up in a hospital emergency room, which increases health-care costs for everyone.”

Despite the image of Northern Virginia as a wealthy enclave where median household income exceeds $100,000 in some places, the region has growing numbers of uninsured low-income people in every jurisdiction, Mathews said.

Poor oral health is linked to serious health conditions later in life, including heart disease, diabetes and strokes.

And it can make employment that much more difficult for lower-income adults.

“If you’re looking for an entry-level job at a fast-food restaurant and you’ve lost your front teeth, what’s the chance that you would get hired to greet the public?” Mathews said.

Health experts say people tend to put off dental care until there’s a real problem. In addition to cost and lack of dental coverage, lower-income adults cited lack of transportation and child care among other factors that kept them from the dentist.

In Virginia, Medicaid covers only “medically necessary oral surgery” for adults but not checkups or root canals, the report said. There are only a handful of nonprofit safety-net organizations for the under-insured or uninsured, and they have long waiting lists.

Three months after the Northern Virginia Dental Clinic’s Loudoun site opened in October, it had a waiting list of 300 patients, Mathews said. Although some area dentists volunteer at clinics or provide their services at reduced rates, the need far exceeds the number of dentists willing to provide those services, the report said.

The foundation has given $800,000 in grants in the past five years to organizations that provide oral health for lower-income residents. Mathews urged more providers to take advantage of a program that provides tax credits for providers who treat dental patients at reduced costs.

The survey was based on a poll of 1,300 adults in Arlington, Fairfax, Loudoun and Prince William counties and the cities of Alexandria, Fairfax, Falls Church, Manassas and Manassas Park. Those whose households made less than $40,000 were considered lower-income. Using 2009 Census data, the survey estimates there are 186,000 such adults and more than 1.5 million adults who earn more than $40,000 in Northern Virginia.