Bilal Ahmed covers his face as he leaves D.C. Superior Court with his attorneys, Peggy Bennett and Barry Coburn. The Georgetown dentist pleaded not guilty to charges that he sexually assaulted a patient who was under anesthesia. (Keith Alexander/The Washington Post)

A Georgetown dentist pleaded not guilty in D.C. Superior Court on Thursday to charges that he sexually assaulted a man who was under anesthesia to have a tooth removed.

Bilal Ahmed was arrested by New York authorities Jan. 7 at John F. Kennedy International Airport after deplaning a flight from Pakistan. Ahmed, 43, of Rockville, Md., was released after posting $50,000 bail in New York to return to the District for his first court appearance.

In court records, prosecutors say the alleged offense occurred May 21, 2014, at Ahmed’s practice, Universal Smiles, at 2311 M St. NW. According to documents, the man went to Ahmed’s practice for a cracked tooth. Ahmed told the patient that the tooth had to be extracted and that he had to use nitrous oxide, commonly known as laughing gas, to sedate the patient during the procedure. The patient was told that his insurance did not cover the nitrous oxide and that he would have to pay out of pocket.

According to the documents, Ahmed had an assistant in the room with them when the gas was being administered. But later, the assistant left the room and closed the door, leaving Ahmed and the patient in the office.

The patient said he woke to find his mask askew and the dentist forcing him into oral sex, according to the court papers. Ahmed then escorted the patient back to the recovery room, the papers said, and the man left Ahmed’s practice two hours later.

After contacting police, the patient called Ahmed six days later in a recorded phone call arranged by a detective. During the call, Ahmed asked the patient how he was feeling. The two spoke about meeting for lunch. The patient, with two officers listening, described what he remembered happening. “You know I’m not crazy,” the patient told Ahmed. “No, not crazy,” Ahmed responded, according to the documents.

At one point, the dentist laughed and said hallucinations can happen when using nitrous oxide, the documents say. At another point, when the patient asked whether he had been hallucinating at the time of the alleged incident, Ahmed said, “No.”

At the hearing, Judge Renee Raymond ordered Ahmed’s release but required him sign up for GPS monitoring as part of the court’s intensive supervision.

Raymond also ordered Ahmed, the married father of six children, to have no contact with the victim and not to practice dentistry.Ahmed’s next hearing is scheduled for Feb. 17.

After the hearing, Ahmed, his wife and his attorneys declined to comment.

D.C. police are asking anyone with information about Ahmed to call the sexual assault unit at 202-727-3700 or the police command center at 202-727-9099.