New York Times

WASHINGTON — Several justices at Supreme Court arguments on Tuesday sounded troubled over efforts by a North Carolina dental board to drive unlicensed teeth-whitening services out of business.

“The object of the antitrust laws is to prevent private individuals who compete with each other in business from getting together and making agreements,” Justice Stephen G. Breyer said. “That kind of interest seems present here.”

As the argument progressed, though, some justices seemed to grow frustrated with the case, musing about how hard it would be to rule against the dental board without also upending professional regulation in other fields.

“It seems to lead to a case-by-case, state-by-state, board-by-board inquiry by the federal courts as to whether the members of a regulatory body are really serving the public interest or whether they have been captured by some special interest,” Justice Samuel A. Alito Jr. said.

The case, North Carolina State Board of Dental Examiners v. Federal Trade Commission, No. 13-534, illustrated a common worry for the justices — that the resolution of the dispute will have negative consequences in other cases.

The dental board has eight members, six of whom are required to be practicing dentists and are elected by other dentists. The board also includes a dental hygienist, elected by other hygienists, and a consumer appointed by the governor.

Starting around 2003, the board grew displeased with the rise of commercial teeth-whitening services in spas and shopping malls, and sent dozens of cease-and-desist letters to the services and their landlords.

Justice Ruth Bader Ginsburg said those letters were out of bounds.

“Why should there be an antitrust exemption for conduct that is not authorized by state law?” she asked. “The objection here was that this board was issuing a whole bunch of cease-and-desist orders. They had no authority to do that. No authority at all.”

The Federal Trade Commission filed a complaint against the board, accusing it of anticompetitive behavior. The board responded that it was shielded from the complaint because it was a state agency incapable of violating the federal antitrust laws.

The United States Court of Appeals for the Fourth Circuit, in Richmond, Va., rejected that contention, saying that a state agency “operated by market participants who are elected by other market participants is a private actor” and is subject to the antitrust laws unless it is actively supervised by the state.

The central question for the justices was whether such active state supervision was required for the dental board to be protected from antitrust suits. Hashim M. Mooppan, a lawyer for the board, said no, as the board members themselves were state officials.

“The federal antitrust laws shouldn’t be interpreted to second-guess whether a public official is really private just because they have a conflict of interest,” he said.

But Justice Breyer said that at least some kinds of boards required supervision. Were the state to tell wine merchants or truck drivers that they were free to set their own prices so long as they were reasonable, he said, “they can do that if, and only if, there is supervision.” Otherwise, he said, “they might get out of hand.”

Justice Ginsburg seemed to agree. She said of the dental board that it was both the “state actor” and a “private actor.”

“So yes, you can have such a board,” she said, “but there needs to be a check of supervision.”

Justice Anthony M. Kennedy also appeared to be troubled by the apparent conflict of interest. “If the board says we think what’s good for dentistry is good for North Carolina,” he said, “our cases say that’s not enough because you’re pursuing your self-interest.”

Mr. Mooppan cautioned the justices not to disrupt “the most traditional way of regulating the professions that states have historically used and have consistently used for a long time.”

A supporting brief from the American Medical Association and several other medical groups said that a ruling against the dental board would discourage doctors from serving on professional boards and disrupt a “150-year tradition.” Several bar associations filed a brief making similar points on behalf of lawyers.

Justice Antonin Scalia said a ruling against the board could also threaten judges. “What do you do about a state Supreme Court that sets the ethics rules for the legal profession, including what constitutes the unauthorized practice of law?” he asked.

Justice Breyer said he would draw the line at neurologists, allowing them to decide who can practice brain surgery. “I don’t want a group of bureaucrats deciding that,” he said. “I would like brain surgeons to decide that.”

On this point, at least, Justice Scalia agreed. “I want a neurologist to decide it,” he said.