Tammy Smith had every excuse for not going to a dentist.

The 46-year-old homemaker from Arlington had no health insurance and could not afford treatment. And she was terrified of dentists.

A toothache, however, can be very persuasive.

The waiting list for dental care at the Catholic Charities Free Health Care Center on Ninth Street, Downtown, is a year long and bears hundreds of names. Still, Ms. Smith signed up.

"She was a real dental phobic," said Dr. Richard DeFilippo, one of the dentists who volunteers at the center, where he has treated Ms. Smith three times in the past couple months. "But she's been great. We found a cyst in her mouth that could have been much worse without treatment."

The people who sit in the waiting room of the center have different ailments. They also have something in common -- they don't have health insurance and they don't qualify for Medicare or Medicaid.

"They're often described as 'the working poor,'" said Diane Redington, administrator of the facility.

For these people with few options to obtain health care, the center has become an increasingly packed safety net.

When Catholic Charities opened the center in November 2007, it operated three days a week, with volunteer doctors seeing 40 patients a month.

"We didn't know what we were in for," Ms. Redington said. "The first week we were open, we had over a thousand phone calls, so we knew we were on to something here."

As the economy has worsened in recent months, Ms. Redington said, the center's waiting list has grown longer.

The center now is operating five days a week and some evenings. A half-dozen paid employees and nearly 150 volunteers treat almost 600 patients a month for medical conditions and dental needs.

In 2008, the center saw 5,200 people. This year, it's on track for 7,000.

"We're seeing more people getting laid off, and we didn't see that at the beginning," Ms. Redington said.

Melissa Fox, spokeswoman for the state Department of Insurance, said a million Pennsylvanians were without health insurance last year -- the most recent year for which statistics were compiled.

The total in Allegheny County, she said, was close to 70,000 residents, or roughly 9.5 percent of the adult population. That doesn't include nearly 6,000 uninsured people 18 and younger.

Dan Laurent, spokesman for West Penn Allegheny Health System, said that in the past six months officials at its hospitals have seen an increase of more than 20 percent in the number of people seeking treatment who are underinsured or lack insurance altogether.

"All of the hospitals deal with this to a degree," he said. "Because if someone shows up at your emergency room, you cannot turn them away. You have to treat them.

"I have to think the economy is continuing to drive patients like this to hospitals. And it's impacting the operational margins of our hospitals, as it is every hospital."

The Catholic Charities center is dependent upon government grants and corporate donations to make ends meet. Ms. Redington said its funding is in place for another year of operation.

The doctors volunteer their time. Nearly all of the equipment is second-hand, donated by doctors who have upgraded their own facilities.

"Some people think we're in the basement of a church," Ms. Redington said. "But we're very proud of what we have here. We believe people get the same care here that they'd get anywhere else."

Patients see general practitioners, as well as specialists, such as urologists, dermatologists, gynecologists, psychiatrists and physical therapists. Ms. Redington said the physicians come to the center and offer their services.

"We need more dentists," she said. "The demand is huge. And it's so important. In order to get on a transplant list or to have chemotherapy or hip replacement surgery, patients [first] have to be dentally cleared. And if you don't have dental insurance, it's so expensive.

"If you have a toothache and you don't have any money, it's pretty hard to get anybody to see you. But if you have a bellyache, you can go to a hospital emergency room and somebody will help you."

Beatrice Woods, 55, of Crafton Heights, has a part-time job pressing clothes but no health benefits. She turned to the center for treatment of her diabetes and because she wanted dentures to replace her teeth, most of which were so decayed that they had to be pulled.

"I came for my teeth," she said. "I want a nice smile."

But Ms. Woods is still on the dental waiting list, so she and the volunteers focus on controlling her diabetes.

"I like the people here," she said. "They're caring. When I'm here, everybody is nice to me, they talk to me."

Ms. Smith, said she is much more comfortable in a dentist's chair after having been to the center.

"[The staff] takes more time, they answer your questions," she said. "They're real pleasant and they help you."

Dr. DeFilippo, the dentist treating Ms. Smith, said the experience at the center has been as rewarding for him as it might be for the patients.

"I have been in private practice for 30 years, and these are the most grateful patients that I've ever come across," he said. "They're happy to be served and treated."