CHICAGO (CBS) — A man impersonating a dentist may have performed hundreds of procedures on patients before being arrested on Thursday, police said on Friday.

Cook County Sheriff’s police, acting on a tip, learned that Alberto Nunez was allegedly operating a dental practice out of a home at 2057 N. Emerson St in unincorporated Cook County.

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Nunez, of the 7800 block of S. Kenton Avenue in Chicago, is charged with a felony count of practicing dentistry without a license and a misdemeanor charge for unlawful possession of hypodermic syringes.

Cook County officials photographed the dentist chair where they say Alberto Nunez was operating a bogus practice.

Cook County Sheriff Tom Dart says patients should have skeptical.

“You’re talking about a dentist’s office in the back of someone’s house,” he says. “There should be a couple of flags flying here.”

According to police, Nunez claimed he went to dental school in Mexico City and may have been practicing for about two years.

Nunez was arrested after an undercover officer made an appointment to see Nunez on Thursday. The officer had to wait for the appointment because of Nunez’s busy schedule, according to Nunez’s receptionist, police said.

While the officer was waiting for her appointment, a patient who left Nunez’s office was stopped by police and told them he had a root canal completed.

Officers then entered the dental office and found a dental chair, lights, plates, tools, syringes, and an x-ray machine and much more.

Investigators concluded that he was performing all sorts of dental procedures such as root canals, bite impressions, cleanings, x-rays, surgical dental procedures and even braces.

Medical equipment inside the office of Alberto Nunez. (Credit: Cook County Sheriff)