The dentists and their assistants often delivered the bad news when the patient was already in the treatment chair, in pain and in no position to read fine print, New York City officials said.

The patient — typically poor and older — needed thousands of dollars of work, and insurance would not cover it, the dentist would tell them. But there was a way forward: Just sign up for a convenient payment plan.

But what the two dental practices in Canarsie, Brooklyn, were not telling the patients was crucial, the city said.

The claims that the patients’ insurance would not cover the procedures were often false, the city said. The convenient payment plans were essentially high-interest loans with rates as high as 27 percent. Sometimes, the city said, patients were signed up for them without their consent at all.

On Wednesday, the New York City Department of Consumer and Worker Protection said it had sued the practices, Canarsie Family Dentistry and New York Family Dentistry, in State Supreme Court in Manhattan, accusing them of false advertising and deception and seeking restitution and other penalties.

“No one in pain should be treated like a payday,” the agency’s commissioner, Samuel A.A. Levine, said in a statement. “When dental providers exploit New Yorkers who desperately need care, New York City will halt their predatory practices and hold them accountable.”

Neither practice responded to phone calls or emails seeking comment on the city’s accusations. New York Family Dentistry, which has three locations in the neighborhood (one of which has a sign out front reading “All Smiles & insurance accepted”), and Canarsie Family Dentistry, which has one location, are not connected, the city said.

The city said that the practices pushed the credit products on their patients for one reason: “They get immediate payment in full, right away,” Melissa Iachán, the consumer protection department’s deputy general counsel, said. “There’s no waiting, no negotiating with insurers or accepting partial payment.”

The suit, filed on July 17, details about a half-dozen case histories. Ms. Iachán said the city expected to hear from many more patients who had been similarly hoodwinked.

One patient named in the suit, Carol Romain, was told by the staff of Canarsie Family Dentistry that her insurance would not cover the extraction, crown and antibiotics they said she needed, the suit said. The practice at first refused to try to submit a claim to Ms. Romain’s insurer and would not even provide her the procedure codes for her to submit a claim herself, so she was forced to choose between paying $1,500 out of pocket or tolerating the pain.

While she was in the dental chair, the staff gave her husband a document to sign that he thought was necessary to submit a claim to insurance. But the couple later learned that it was a credit application and that the credit company had paid Canarsie Family Dentistry $3,000 on the spot that the couple was now liable for.

Lola Parchment, a retired nurse’s aide, came to Canarsie Family Dentistry in 2023 seeking relief from dental pain and filled out some forms that she understood to be routine intake paperwork, according to the suit. She got a simple cleaning, which she believed her insurer would cover, but when the staff told her she needed thousands of dollars worth of work, she said she could not afford it and left.

“All they did was clean my teeth and tried to get me to borrow thousands of dollars I did not want to borrow,” Ms. Parchment said in a phone call on Wednesday.

In 2025, she got a letter from a collection company telling her she was being sued for $5,291 for charges associated with Canarsie Family Dentistry.

“I was shocked when I got the paper for me to go to court,” she said. “They’re preying on elders and poor people. They’re terrible.”

Yasmin Breeden, a 67-year-old woman on Medicaid and Medicare, went to Canarsie Family Dentistry for a partial denture installation and was told that all her remaining teeth needed to be extracted and replaced with permanent dentures, Ms. Iachán said.

Rather than billing Medicare or Medicaid, Ms. Iachán said, the practice told Ms. Breeden she needed to pay $1,000 out of pocket immediately and take out a loan for another $5,000. The dentist pulled her teeth but failed to install the screws for the dentures properly. When her daughter tried to get the practice to correct the problem, she was told that Ms. Breeden would need to take out another $10,000 loan, Ms. Iachán added.

Within the last few weeks, Ms. Iachán said, the practice contacted Ms. Breeden and her daughter again. This time, employees threatened to send her account to collections.