With her children grown, Trisha Eck thought it would be fun to go from being a stay-at-home mom to a small entrepreneur – so she rented a room at a medical spa, where she started her own business, Tooth Fairies Teeth Whitening.

She purchased equipment and supplies from a vendor she met at a trade show, including non-prescription strength teeth whitening gels. Customers could purchase her products as a take home kit or apply them to their own teeth while visiting the spa. Since she’s not a dentist, Eck says she never performed the treatments on customers but was there to offer instructions.

“Everybody wants a white, happy smile,” Eck said. “I loved what I did. It made people happy. It was a fun job to have, and it was a nice way to help my family.”

But state regulators weren’t smiling. This spring, Eck received a cease and desist order from the Georgia Board of Dentistry, after one of its investigators determined her business was an unlicensed dental practice.

“He comes from the dental board, and he’s telling me he can shut me down. He can fine me; I could face prison time,” Eck said. “That’s a little intimidating.”

Eck closed her business to avoid any legal consequences but insists she did nothing wrong. She says she merely provided customers instructions and a clean place to apply over-the-counter whitening treatments to their own teeth.

“You don’t see them going after people who do tongue piercings,” Eck said. “To me, that’s much more invasive than teeth whitening.”

Eck’s predicament attracted the attention of the Institute for Justice. The libertarian law firm has filed a federal suit against the Georgia Board of Dentistry, arguing that the dentists who serve on it are trying to protect their profession from low-cost teeth whitening alternatives.

“They’re using government power to outlaw their competition [and] keep prices high,” said Larry Salzman, the Institute’s lead attorney on the case. “That’s just not only bad policy, it’s unconstitutional.”

The Georgia Board of Dentistry declined to comment on the issue because of the pending litigation.

And Georgia is not alone. The Institute for Justice has filed similar legal challenges to dental boards in Alabama and Connecticut. And the U.S. Supreme Court has agreed to hear a case brought by the Federal Trade Commission against the North Carolina State Board of Dental Examiners over cease and desist orders the state agency issued to non-dentist teeth whiteners.

According to the Institute for Justice, dental regulators in at least 25 states have ordered teeth whitening businesses to shut down, and at least 14 states have changed laws or regulations in recent years to exclude non-dental professionals from offering teeth whitening services.

Although teeth whitening services provided by non-dentists are generally less expensive than those in a medical setting, many dental professionals advise caution.

“Patients who are considering having their teeth whitened by non-dentists should first visit their dentists to make sure their teeth and gums are healthy,” the American Dental Association (ADA) said in a written statement to Fox News. “White teeth are not necessarily healthy teeth.”