A South Portland woman is one of 11 named plaintiffs in a class-action lawsuit against Aspen Dental Management and its majority shareholder about alleged “sham” owners and deceptive practices.

Aspen Dental has seven locations in Maine that opened from 2006 to 2008. Thousands of Mainers could be part of the class, said Brian Cohen, one of the New York lawyers for the plaintiffs.

“We’re fighting for thousands of aggrieved patients of Aspen, and hopefully we’re going to right the many wrongs that were committed against them,” Cohen said Friday.

Named as defendants are Robert Fontana, president and CEO of Aspen Dental Management; and Leonard Green & Partners, the private equity firm that has majority ownership of the company.

Isabelle Reali, 59, a certified nursing assistant, went to the Aspen Dental location in South Portland in July 2010 because her dental insurance was accepted there and because of advertisements for free examinations and X-rays, according to the complaint filed in the Northern District of New York on Thursday.

After a brief examination, she was “whisked” into a business office where an office manager persuaded her to commit to a treatment plan that included full extractions and dentures before encouraging her to sign up for a health care credit card for the amount her insurance would not cover, according to the complaint. Reali’s insurance was “maxed out” and the credit card was charged before she had any procedures.

The complaint says that Aspen Dental clinics, including the one in South Portland, are not owned and operated by the licensed dentists who provide the care, as they claim. The complaint accuses the defendants of practicing dentistry unlawfully.

In a prepared statement, Aspen Dental Management said the allegations in the lawsuit “are entirely without merit.”

Company spokeswoman Kasey Pickett said doctors own the clinics and Aspen Dental Management provides support services such as marketing, accounting and other administrative functions. She said the crux of the business model is freeing up doctors so they can focus on care.

The company said it provides support to more than 350 dentist-owned practices in 22 states. Its Maine locations are in Biddeford, South Portland, Portland, Topsham, Waterville, Bangor and Augusta.

Further details about Reali’s experience with Aspen Dental — including the cost of the treatment and whether she followed through with the plan — are not in the complaint. Reali could not be reached for comment Friday.

Cohen said that because of the pending litigation, he would not allow plaintiffs to speak to the media and would not provide additional information about their experiences with Aspen Dental.

The lawsuit is on behalf of 11 people in 11 states. The Associated Press reported that their lawyers are seeking class-action status that could cover tens of thousands of current and former patients.

The allegations in the lawsuit struck a chord with Mark Malm, a retiree who lives in Biddeford.

Malm, 69, said he went to Aspen Dental in Biddeford because his regular dentist didn’t take his insurance. He said he paid about $3,500 out of pocket for treatments he received during three visits in 2010.

He and his wife, Diane, became suspicious when the prices increased in successive visits and they sought a second opinion from his regular dentist.

Malm’s regular dentist now is treating his periodontal disease for $125 a visit, three times a year, Malm said. One big difference is how many pockets of receding gums are injected, he said.

His regular dentist does the injections on only four or five pockets, while he had 29 treated at Aspen Dental, he said.

“Scare tactics is basically what it was. ‘I’m going to lose my teeth if I don’t get this done,'” he said.

Greg Hebert, 53, of Biddeford, said he went to Aspen Dental several years ago, when he didn’t have insurance. Hebert, who said he has bone loss in his jaw that causes his teeth to fall out, knocked out several teeth in an accident.

Hebert, who works in construction, said he was surprised by how much the work cost, about $5,400. He said it included fillings, deep cleaning and partial dentures.

He said he lost the partial dentures, which he believed cost about $3,500, and got new ones from a denturist. The replacements cost about $1,900, he said.

“Maybe I was right when I was questioning how much it cost,” he said.

Representatives for Aspen Dental could not be reached to respond to the accounts of Malm and Hebert.

The Maine Attorney General’s Office has one consumer complaint filed against Aspen Dental within the past year. A representative said the case is unresolved, which could indicate that it is still in process or that mediation failed. She said she could not provide additional information.

The Maine Board of Dental Examiners handles complaints related to care. The person with access to those records was not available Friday, and the information cannot be located until early next week, said Doug Dunbar, a spokesman for the Department of Professional and Financial Regulation, which includes the board.

In 2010, Aspen Dental reached a $175,000 settlement with the Pennsylvania Attorney General’s Office about misleading information about discounts, consultations, financing and other promotions.