CHICAGO - More Americans are turning to the emergency room for routine dental problems - a choice that often costs 10 times more than preventive care and offers far fewer treatment options than a dentist's office, according to an analysis of government data and dental research.

Most of those emergency visits involve trouble such as toothaches that could have been avoided with regular checkups but went untreated, in many cases because of a shortage of dentists, particularly those willing to treat Medicaid patients, the analysis said.

The number of ER visits nationwide for dental problems increased 16 percent from 2006 to 2009, and the report released Tuesday by the Pew Center on the States suggests the trend is continuing.

In Florida, for example, there were more than 115,000 ER dental visits in 2010, resulting in more than $88 million in charges. That included more than 40,000 Medicaid patients, a 40 percent increase from 2008.

Many ER dental visits involve the same patients seeking additional care. In Minnesota, nearly 20 percent of all dental-related ER visits are return trips, the analysis said.

That's because emergency rooms generally are not staffed by dentists. They can offer pain relief and medicine for infected gums but not much more for dental patients. And many patients are unable to find or afford follow-up treatment, so they end up back in the emergency room.

"Emergency rooms are really the canary in the coal mine. If people are showing up in the ER for dental care, then we've got big holes in the delivery of care," said Shelly Gehshan, director of Pew's children's dental campaign. "It's just like pouring money down a hole.

"It's the wrong service, in the wrong setting, at the wrong time," she said.

The center in Washington, D.C., is a division of the nonprofit Pew Charitable Trusts.

Pew researchers analyzed hospital information from 24 states, data from the federal Agency for Healthcare Research and Quality and studies on dental care.

Not all states collect data on ER visits for dental care, but those that do reveal the trend, Gehshan said.

In 2009 alone:

• Fifty-six percent of Medicaid-enrolled children nationwide received no dental care.

• South Carolina ER visits for dental-related problems increased nearly 60 percent from four years earlier.

• Tennessee hospitals had more than 55,000 dental-related ER visits - five times as many as for burns.

Using emergency rooms for dental treatment "is incredibly expensive and incredibly inefficient," said Dr. Frank Catalanotto, a professor at the University of Florida's College of Dentistry who reviewed the report.

Preventive dental care such as routine teeth cleaning can cost $50 to $100, versus $1,000 for emergency room treatment that may include painkillers for aching cavities and antibiotics from resulting infections, Catalanotto said.

These infections can be dangerous, especially in young children, who may develop fevers and dehydration from preventable dental conditions. In Florida, for example, 200 children were hospitalized in 2006 for those types of infections, he said.

The recession has contributed to the trend, Catalanotto added. When a family member loses a job, dental care may take a back seat to food and other necessities.

Part of the problem is low Medicaid fees for dentists. In Florida, only about 10 percent of dentists participate in the state Medicaid program, he said.

The numbers also are rising in hospitals in Illinois, where dentists have complained about low Medicaid reimbursements.

Pekin Hospital in the central Illinois town of Pekin has seen a significant increase in ER patients with "very poor dental health," said Cindy Justus, the hospital's ER nursing director. They include uninsured patients and drug abusers, and many are repeat patients.

"There's just not a lot of options" for them, Justus said.

Shortages of dentists, especially in rural areas, have contributed to the problem, Gehshan said.

She said the Pew center is working with states to develop training for dental hygienists and other non-dentists in treating cavities and other uncomplicated procedures. Other potential steps include increasing water fluoridation and use of dental sealants.

Putting plastic sealants on molars can prevent cavities, but "children at the lowest risk are most likely to get them. It needs to be the opposite," Gehshan said.