Surviving on a meager $1,300 a month, 87-year-old Theresa Ferritto fretted about the cost when her dentist told her she needed two teeth pulled.

She figured an oral surgeon would be too expensive. So she decided to try out a dental chain that promoted steep discounts in its advertisements. She went to an Aspen Dental office just outside Cleveland.

Ferritto said Aspen Dental wouldn’t just pull the teeth but insisted on a complete exam. She was bewildered when they finally handed her a treatment plan four pages long. Total price: $7,835.

Ferritto could not afford it, but Aspen Dental signed her up for a special credit card, with monthly payments of $186 for five years. She blames herself for signing the papers.

“I made a big mistake going there,” she says. “I should have known better.”

After a day of cleanings and two fillings, Ferritto asked her son for help. He called Aspen Dental to complain but said he got nowhere. So they turned to the state Attorney General.

Aspen Dental took all charges off her credit card for treatments she hadn’t yet received. But said the $2,540 she was charged for two fillings and cleanings was appropriate.

Aspen Dental charged Ferritto $350 for an antibiotic put next to teeth the dentist was going to pull, a charge other dentists say makes no sense. There were four separate charges for an antibacterial rinse similar to Listerine for $129. There was even a $149 charge for an electric toothbrush that Ferritto didn’t even know she had, until she recently retrieved an Aspen Dental bag from her garage and found it inside.

Imagine how many groceries that would buy, she sighed.

A class-action lawsuit accuses Aspen Dental, one of the nation’s largest corporate-dental chains, of illegally owning dental practices and of deceiving patients.

A joint report by the Center for Public Integrity and PBS FRONTLINE titled “Dollars and Dentists” reported in June that Aspen Dental’s practice of serving patients who cannot afford a dentist has led to complaints of patients being locked into debt as well as being overcharged and given unnecessary treatments.

The lawsuit brought by 11 patients alleges that Aspen Dental owns and controls its 358 dental clinics in violation of laws in 22 states which allow only dentists to own a dental practice. The lawsuit was filed yesterday in federal court in Aspen Dental’s home state of New York.

Aspen Dental said Friday that “the accusations that were made in yesterday’s filing are entirely without merit.” The company is owned by a private-equity firm, Leonard Green & Partners, and markets to patients who often cannot afford to go to a dentist.

The company says that it also provides support services to dental offices owned by local dentists.

“The dentists and staff at Aspen Dental offices around the U.S. provide access to high quality, affordable dental care for millions of patients,” the Syracuse-based company said. “Their singular commitment is to do what’s right for their patients.”

However, attorneys for the patients, Brian Cohen and Jeffrey Norton, say in the lawsuit that Aspen Dental trains the dentists and sets production goals for them, accusing the company of illegally practicing medicine.

A leading Republican in the Texas legislature, who says she’s outraged by allegations that corporate dental chains put profits ahead of patients, has introduced a bill that would allow the state to regulate chains and forbid them from forcing dentists to meet revenue quotas.

A joint investigation by the Center for Public Integrity and PBS Frontline last summer found that two of the largest dental chains owned by private-equity firms, Aspen Dental Management and Kool Smiles, put pressure on its dentists to meet production goals, prompting complaints of overbilling and unnecessary treatments.

Both companies deny this. And a coalition of dental chains in Texas contends that their dentists have total control over patient care. But the chief sponsor of the bill remains skeptical.

“Several reports, including the Frontline program, have uncovered outrageous activities involving the illegal enticement of patients, especially among our Medicaid providers and often involving dental service organizations,” said Republican Sen. Jane Nelson, who chairs the Senate’s Health & Human Services committee.

Nelson did not name a specific chain. Aspen Dental does not accept Medicaid and has no offices in Texas. But Kool Smiles has clinics throughout Texas, and public records show that the state Attorney General has been investigating Kool Smiles for Medicaid fraud.

Texas has been embroiled in a Medicaid fraud scandal for the past couple of years. The initial focus was on overbilling Medicaid for unnecessary braces on children. But the scandal has since widened. State authorities said last October that beyond braces, they’ve identified 89 dental providers they suspect of overbilling Medicaid by $154 million.

Sen. Charles Grassley, R-Iowa, says that his investigators have found evidence of abuses by corporate dental chains treating children on Medicaid.

For months now, Grassley’s staff has been asking questions of three dental chains serving poor children on Medicaid. Each is owned by a private-equity firm. The chains are Kool Smiles, Small Smiles and ReachOut HealthCare America.

“We’re finding that these dental practices, under pressure from owners who are not licensed dentists, have been providing services with the highest Medicaid reimbursement levels more often than less expensive, arguably more appropriate services,” Grassley said.  “There are legitimate concerns that children are receiving unnecessary care, sometimes in a traumatic way, and taxpayers are paying for it.”

Earlier this week, a joint investigation by the Center for Public Integrity and FRONTLINE, revealed that the Atlanta-based chain Kool Smiles’s business model of serving kids on Medicaid has led to complaints that it over-treats children. The company has been accused by regulators in Georgia and Connecticut of overusing expensive stainless-steel crowns to treat small cavities.

Kool Smiles vigorously denies this, saying that it offers quality care to children in dire need. It is the largest Medicaid dental chain with 129 offices in 15 states and the District of Columbia.

Grassley said, “You have dentists under pressure to perform more services than may be necessary — giving a child a crown instead of a filling, for example — because of a bonus payment structure that creates the wrong incentives.”

Dental care can be a matter of life and death. Yet millions of Americans can't afford a visit to the dentist.

An investigation by the Center for Public Integrity and FRONTLINE reveals the shocking consequences of a broken safety net. Corporate dental chains are filling the gaps in care. But in some cases they are allegedly overcharging patients or giving them unnecessary treatments. Children on Medicaid are vulnerable to having expensive stainless-steel crown needlessly put over tiny cavities. And adults lured by ads for $249 dentures can be loaded down with thousands of dollars in high-priced credit card debt.

Center senior reporter David Heath and FRONTLINE producer Jill Rosenbaum investigate the problems with corporate dentistry in stories that publish June 26 and 27, and air 10:00pm ET, June 26 on PBS. Join us here on Wed., June 27 for live conversation with the reporting team.